How to make a convenient video presentation?

Question

Video

Good day.
Periodically we make a presentation of a new product to partners and buyers. Up to this point, we did this:
- create a presentation in After Effects;
- cut into pieces;
- insert pieces on slides in Powerpoint;
But it turns out terribly crooked and in general some kind of perversion.
In any case, the presentation will be created in a separate program and output to a video file, because. consists almost entirely of 3d objects and effects that cannot be repeated in a regular presentation program. Therefore, you need a simple and convenient tool for managing video fragments and quickly transitioning between them.
For example: the first part of the video is played and the speaker speaks, and at this time the last frame remains in the background or the entire segment is played cyclically. After that, the next part begins or, if there are any questions, the previous one.
How can this be implemented?
Thank you very much in advance for your reply.

Answer 1

I threw a small web application for you qw0101.github.io/videopresentation