[ENHANCEMENT] Timeline playhead drag (scrubbing) should use timeline cache (playback quality)
Dragging the playhead, aka scrubbing, should be considered "playback". I submit that grabbing the playhead and moving to to your new desired location is likely very common and intuitive.
Presumably one sets up playback quality for performance and paused for a better view. Dragging the playhead should operate as fast as Hitfilm is able to, which means using playback quality settings. When the mouse is released, aka dragging stopped, then paused quality can trigger.
If playhead dragging is considered playback then the timeline cache can be used when available. Even better performance than playback quality.
Hitfilm has always considered playhead movement as "paused" view display. I've mentioned scrubbing should be playback before. The new timeline caches makes this curious scrubbing choice even more curious. As it makes the time spent creating the timeline cache less useful.
Only if the paused view (resolution and quality) are the same as playback does the timeline cache get used. This negates the application feature of having play and paused quality modes.