Neat to see more tools like this out there.
Great for any retromachines that can't / won't run the modern web (and things like Lynx and EWW) and accessibility purposes.
I'll have to take a look at how it's parsing the pages. Brow.sh is usually my goto for these use cases, but that's using a whole Firefox to do the rendering.
Also not Framasoft, but for your search question their Sepia Search https://sepiasearch.org/ would be your best bet to get hits across known Peertube instances/platforms.
Your favorite Peertube instance/platform has its own front page, and they've done a bit of work in the Android app to have an explore tab to have similar across its tracked instances.