Take the climb to a real branch point, and find the cadence has a third column

FINDINGS 70, and it closes ROADMAP P6.  65.6 recorded that "the slack table is
here, but 51.3's refill climb with a second consumer through a real branch point
is not", and 67.6 repeated it verbatim two sessions later.
tools/analysis/36_branch_audio.py is that run: 51.3's surplus model, 56.3's 612
real branch points, 32's cadence arithmetic, both containers' headers and the
buffer constants of the player 68 measured, in one place.  No machine -- all
five were already numbers.

AUDIO IS 1.7% OF THE CODEC WIRE AND UP TO 3.30x OF THE CLIMB.  Slack accrues out
of pipe - wire, which is a small difference of two large numbers, so a second
consumer is not priced by its share of the wire -- which is how every budget in
this tree since FINDINGS 8 has quoted it.  At 451.4 KB/s (the container's own
zero-prefill pipe, 49.5) in a 256 KB ring the climb goes 6.70 s -> 22.11 s and
the branch points arriving under it go 482/612 (79%) -> 603/612 (99%).  At 488
it is 1.19x, at 600 it is 1.05x.  Correction to 56.4: it charged audio at
ratectl.AUDIO_KBPS = 7.8, which is 7,812.5 B/s in decimal kB; in binary KB the
figure is 7.6294, so the placeholder was 2.24% high and every column moved in
the flattering direction by less than one part in six hundred of the wire.

AND ON THE PACKED BRANCH THERE IS NO CLIMB AT ALL.  A record goes straight into
GVRAM, so the video lookahead is zero records and 56.4's alarming column is
vacuous when every frame arrives with less lookahead than the one before it.
Acceptance there is a per-frame deadline, not an average, which is why B1 has to
name a burst rate.  The only consumer on that branch with any lookahead is the
audio one: 1.833 s of sound held against 0.000 s of picture.  And at 589.6 KB/s
-- the acceptance figure this project quotes -- the sounded container's surplus
is exactly zero: it plays and never banks a byte, while the silent one climbs
its record in 6.38 s.

THE COST NOBODY HAD COUNTED.  A DLXP2 group is `lump k, then F records`, so lump
k is at a LOWER address than every record of its group but the first, and a seek
to record i finds its audio behind it.  Measured on the 409 within-container
seek targets of the arcade's own graph at the shipped F=11: mean 416.5 ms of
silence entering a branch, median 416.7, p90 750.0, worst 833.3, and only 36 of
409 land on a group boundary.  The other 203 -- the scene changes -- are free by
construction, because lump 0 sits between the header and record 0.  The
container's own start is the one branch point the cadence costs nothing at, and
it was the only one anybody had looked at.

SO THE CADENCE PICK IS REOPENED, on a third column.  32_audio_wire chose F=11 on
padding and RAM; F=1, the cadence it called the worst one, has no group to enter
off-boundary at all, and gives back 12,288 B of RAM for +4.36 KB/s of wire
(0.74% of the acceptance figure).  The alternative is a second read: lump k is
up to 503,808 B behind, so it is a separate command of 7,168 B -- 11.7 ms
against 416, 36x cheaper in time -- and src/player/packed.s starts PG_AK/PG_AKF
at lump 0 and has no audio seek path at all.  Nothing here decides it; the
deciding number is what one more SCSI command costs, and that is B1's.  The
content is not uniform mod F either: the measured mean runs 0.67x..1.23x of a
uniform assumption across the sweep, and the 1.00x at F=11 is a coincidence.

New check.sh stage, ~10 s, and it gates the STRUCTURE and deliberately not the
milliseconds: audio never shortens a climb, the shipped cadence strands most
within-container branches, F=1 strands none, and the lump read is an order of
magnitude cheaper than the silence it removes.

The one thing 70.3 and 70.4 rest on is a DESIGN ASSUMPTION and is printed in the
tool's own output: one container per SCENE (53, 55.1, 56.3).  One container per
sequence makes every seek land on frame 0 and empties both sections.

No encoder, player or container byte moved.

Claude-Session: https://claude.ai/code/session_01194oWYW8DQXK1SZ2DnChW6

README.md

@@ -481,6 +481,35 @@ What it removes is margin — at that rate in a 256 KB ring, **76% of this game'
 branch points arrive before the ring has refilled**, and a 512 KB ring makes it
 90%, because doubling the ceiling does not touch `pipe - wire` (FINDINGS 56).
 
+**And with the second stream on the wire, that climb is a different number.**
+Slack accrues out of `pipe − wire`, which is a small difference of two large
+numbers, so a second consumer is **not** priced by its share of the wire.
+7.63 KB/s of audio is **1.7% of the codec container's wire and up to 3.30x of
+its climb**: at 451.4 KB/s — the rate at which the *silent* container is exactly
+deliverable — the climb goes **6.70 s → 22.11 s** and the branch points arriving
+under it go **79% → 99%** of the game. On the packed branch there is **no climb
+at all**, because a record goes straight into GVRAM and the video lookahead is
+zero records; the only consumer there with any lookahead is the audio one,
+**1.833 s of sound held against 0.000 s of picture**. And at **589.6 KB/s**, the
+acceptance figure this project quotes, the sounded packed container's surplus is
+exactly **zero** — it plays and never banks a byte, which is why B1 has to name
+a burst rate and not only a sustained one.
+
+**A DLXP2 group is `lump k, then F records`, so a seek finds its audio behind
+it.** Read forward from record *i* and the next lump carries frame *(k+1)F*, so
+the frames in between have picture and no sound. On the **409 within-container
+seek targets of the arcade's own graph** at the shipped cadence F=11 that is a
+**mean 416.5 ms of silence entering a branch, worst 833.3 ms, and 36 of 409
+free**; the other 203 branch points — the scene changes — are free by
+construction, because lump 0 sits between the header and record 0. **The
+container's own start is the one branch point the cadence costs nothing at, and
+it was the only one anybody had looked at.** The fix is one extra read of
+7,168 B — **11.7 ms against 416, and no player here has an audio seek path** —
+and the alternative is the cadence 32 called the worst one, F=1, which has no
+group to enter off-boundary and gives back **12,288 B of RAM for +4.36 KB/s of
+wire**. The deciding number is what one more SCSI command costs, and that is
+hardware's (FINDINGS 70).
+
 **Nothing outside-derived is committed here.** The scene graph is not
 redistributable from this tree; it is regenerated from a reader's own clones
 into gitignored `tmp/`, and `tools/import/scenegraph.py` is the single file in
@@ -506,7 +535,9 @@ volume and compares every one of them**, then encodes the same window's audio
 and gates it against ffmpeg's decoder, then asks the emulated MSM6258 which of
 sixteen decoders it is, then gates the DLXP2 container and every one of its
 axes, then measures the audio level off every stream of the game's own footage
-and gates the disc's peak against the chip's clamp, then prints `ALL GREEN`.
+and gates the disc's peak against the chip's clamp, then runs the refill climb
+against the arcade's own 612 branch points with the second stream on the wire,
+then prints `ALL GREEN`.
 
 ## Reproducing this
 
@@ -661,6 +692,12 @@ tools/analysis/  measurement scripts, numbered in the order they were written.
                  a different sound from 687 in one), and what six gains cost on
                  windows drawn over the whole game. --gate asserts those
                  numbers; --recover is the control that kills 66.3's mechanism.
+                 36 puts 51.3's climb, 56.3's 612 real branch points and 32's
+                 cadence in one place: what a SECOND CONSUMER does to the
+                 climb, and what a seek into the middle of an audio group
+                 costs. It reads only DLXSCENE1 and both containers' own
+                 headers, and its one design assumption -- one container per
+                 SCENE -- is printed in its own output.
                  buscost.py is the shared bus-cycle table. The per-block
                  constants live in tools/encoder/vq_hybrid.py and are imported,
                  never copied.