A long conversation stops starting over
Chat mode re-wrote its own compaction summary on every single
message. A fresh wording each time, sitting in the system message —
the opening of the prompt — so everything behind it moved and the
engine could match nothing it had already computed. Measured on
Gemma-4 26B through MLX: 99% of the window reused on the turns
before compaction began, and 0% on every turn after it, plus a whole
extra generation per turn to write the summary again. The summary is
kept now until the conversation outgrows the room it left, and it is
written from the previous summary rather than from a transcript that
gets more elided each time. Same measurement afterwards: 99-100% on
the turns in between.
Reasoning kept in its own field counts against the window again.
Some templates read a turn's thinking from reasoning_content
rather than from the message body, so Chaty splits it out for them —
and the budget counted only the body, reading a whole reasoning
history as very nearly free. Qwen3.8 27B is the one local model that
splits it, and in a fourteen-model sweep it was the one model that
walked off the end of its own window: six turns in a row answered
with "context" and generated nothing, the conversation simply dead,
while the budget still reported room to spare. Same shape as
pictures counting for nothing before 2.1.2. Afterwards the same ten
turns never overflow, and each turn recovers on the next one.
Today's date and the web-search results moved out of the system
message and onto the turn that produced them. A regex on the current
question decided whether the date line was there, and the results
were new every turn — so one question containing the word "recent"
cost two full re-prefills, the turn that added the line and the turn
that dropped it again: 2% and 1% reused, against 81% and 94% around
them. An answer that cited a source now keeps the source, too.
Code mode's cross-turn trim leaves room to grow. It freed exactly
enough to slip back under its ceiling, so the next turn was over
again — the same ceiling-hugging that mid-turn compaction was fixed
for in 2.1.2, on the other side of the turn boundary.
Thinking and web search can no longer both claim to be on. They are
mutually exclusive — a searching turn is sent with reasoning
suppressed — and turning search on from the command palette left a
tick beside Thinking in the Tools menu while every later turn
quietly stopped reasoning. If some of your turns seemed not to
think, this was why, and it was never the model.
A turn with no answer in it now says so. The prompt outgrew the
window and nothing was generated, or the model reasoned to the end
of its budget and stopped before writing anything: all of it used to
land as an empty bubble, or as a turn that vanished on reload.
A GPU load that was quietly cut back says so. After a driver crash
the next load takes fewer layers, and only the bottom of that ladder
was ever reported — the rungs in between just ran slower for no
stated reason.
Settings hover explanations stay inside the window. They were drawn
on the label they belonged to and clipped by the panel's own edge,
which no amount of clamping could fix; they are real elements now,
outside the panel, measured rather than estimated.