interactive video: transition when toggling interactions

A colleague of mine loves h5p, especially interactive video, but she thinks that the transition when toggling interactions including pausing the video is quite hard:

• You can only set a time code down to seconds, but no fractions of seconds. This can make it tricky if you have to use a video that has already been produced, because you cannot time the interruption properly. You would e.g. have to interrupt a speaker in mid-sentence. There's already a pull request for supporting intervals of tenth of a second, but it seems that it still needs some review first.
• The interruption cuts audio in an instant. My colleague thinks it might be nice if there was some some kind of audio transition (optionally), e.g. starting to fade out 0.5 seconds before toggling.
• The overlays pop up directly. My colleague thinks it might be nice if there was some some kind of visual transition (optionally), e.g by gradually increasing opacity.

What do you think about these ideas? And is there anyone who's already working on something similar?