Hi oha
1. I deliberately designed Stroll without reference to user tagging. The goal was to get as close to Roam in functionality, and Roam works with backlinks. Backlinks have the advantage of being less likely to slow down a large file than tags, and don't require you to stop typing in order to use a mousepad to click on things. But of course, you can use tags all you want in Stroll.
Drift
(
https://akhater.github.io/drift/), which was based on Stroll, is set up for displaying tags at the bottom as well as for backlinks. You may or may not find Drift more compatible with your current system.
2. I went to the Stroll site, created a caption field with a different name for the Welcome to Stroll tiddler, then in a separate tiddler pasted
<<tabs "[tag[$:/giffmex/tutorials]]" "">> and the tab for Welcome to Stroll shows what I put in the caption. So I am not sure what you are referring to. Describe what you did, what you expected to happen, and what actually happened, and I will try to figure it out.
3. I don't use GitHub, sorry! I am not a coder, just someone who found a way to combine plugins, viewtemplate tiddlers, and CSS to approximate the feel of Roam in a TiddlyWiki. I am not opposed to you uploading a copy of Stroll to GitHub and adding your own improvements there. I don't make any money off of this project, I just wanted to make something useful for others. Just give it your own name to avoid confusion, like the author of Drift did.