Please critique my premiere pro workflow (not sure I'm doing it correct)

I'm working on around 90-minute tutorials for YouTube. I discuss 10 to 15 various things that I edit in separate premiere pro projects in these tutorials. When done with 1/15 part of the tutorial, I export that file as .mp4. I do the same with the other 10 to 15 project files for the tutorial.

When done with all the individual project files, I export these final mp4 files to the master project file for the final version of the 90-minute tutorial for youtube.

When I add all these mp4 files, I will export the final 90-minute file as mp4 and upload that file to youtube.

I do find this workflow tedious.

I recently came across Productions (https://helpx.adobe.com/premiere-pro/using/production-panel.html), which could help me.

However, I still need to add all the separate project files together for the final masterpiece for YouTube.

I already tried to edit all the 15 separate raw video files in the masterpiece adobe premiere project file, but I will quickly lose my overview of what is what. The big problem with editing a 90-minute video in 1 timeline is moving content, let's say, a 15-minute part of a 90-minute video. I can't find an easy and fast way to select this 15-minute part.
I find it hard to select the correct content because the timeline is that long. I feel zooming in and selecting and dragging isn't the way to go.

The overall question is, what should my process be of editing these videos? Do you know of an easy way to organize a 90-minute how-to tutorial of 11 chapters?