Welcome to TVPaint Community forums !

some of the inline help is very sparse (even in Full mode)
here is one example that could be easily improved to minimise confusion.

Stretch to new framerate

its a confusing option and not just for inexperienced users.... (me !)

Stretch current project to new framerate

when checked the new project duration remains the same.
if the new framerate is higher then the current project, exposures are added, if lower, frames are removed

when unchecked the number of frames in the new project remains the same.

Good point!
Very clear.