Found while checking whether this works in Easy Gen. It does - the knobs render
and persist there through the same shared engine_settings.js - but Easy Gen's
default scene has no anchor image, which exposed a hole: nothing checked that
the scene actually HAS a pinned i2v anchor. On a genuine t2v scene the slide
would have dropped real generated frames and regrown them at the end, for no
benefit at all. This is the "fake t2v" trick; it needs a real anchor to fake
it with. Now refused with that reason in the scene report.
Second guard: if anchor_shift_frames drops FEWER latent frames than the scene
actually pins, part of the anchor survives and stays visible - the exact
outcome the feature exists to prevent. The report now names the pinned count
and the value to raise the knob to.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>