Read-only verification of existing timeline timing, audio routing, and unsaved state in Premiere 26.2.2

We are building a read-only diagnostic on Windows, initially using Premiere UXP. We need to verify an explicitly identified, already-edited sequence without modifying, flattening, relinking, reimporting, or changing the speed of its source video/audio. Nested and multicamera references must remain intact.

We have inspected the Premiere Pro 26.0 C++ SDK for Windows and the SDK guide linked from Adobe Developer Console. Before building a native diagnostic, could you clarify these supported API paths for Premiere 26.2.2?

1. **Complete time remapping.** We found `TransformNodeTime`, `GetNodeTimeScale` (Video Segment Suite v9), and `kVideoSegmentProperty_Clip_TimeRemapping`. Is the keyframe-data format returned for this property publicly specified? Is there a supported way to obtain the complete function, including interpolation, transition/Bezier handles, holds, reverse sections, and time origins? Point samples or a scalar speed do not establish that the entire time function is unchanged. Does `GetNextKeyframeTime` apply to this property, and if so how is its parameter index identified without guessing?

2. **Coverage and identity.** Can Video Segment Suite enumerate every existing source track item, including disabled clips, hidden/occluded tracks, and nested/multicam content? Can its nodes be reliably associated with UXP track items using a supported persistent identity? We found the export source SequenceGUID/SessionFilePath selectors and clip TrackID/start/end properties, but have not validated this association in a native plugin. We will not use a segment hash alone as proof of unchanged layout, since the guide notes it may survive a time shift.

3. **Existing audio relationships.** Which supported read-only API returns each existing audio track item's source-channel mapping, referenced nested source channels, and AV linked-item membership? We need the state of already-existing timeline items, not just current project-item defaults, mixer channel labels, or a rendered audio mix.

4. **Consistent unsaved state.** Is there a supported revision or snapshot mechanism covering both video and audio editing state, including unsaved changes, that can be bound to these reads? UXP `lockedAccess` has a synchronous callback; how can a sequence of asynchronous reads be proven to describe one consistent revision? Does acquiring C++ video segments provide any documented immutability guarantee, and what corresponding guarantee applies to audio?

We have not installed or loaded a native diagnostic and are not claiming C++ runtime support from header declarations. We can build minimal synthetic reproductions after confirming the supported approach. If any requirement is unsupported in 26.2.2, confirmation of that limitation and a supported non-destructive alternative would be helpful.