Support for all of those systems is listed explicitly in the Kickstarter and the preview PDF.

Glad to help! I’m somebody who wishes more videos were blog posts so I totally get it. I tend to enjoy Matt Colville’s videos, though.

There’s a short summary at https://shop.mcdmproductions.com/collections/the-talent-and-psionics/products/the-talent, with a few excerpts from the PDF (in images, unfortunately), but I felt like in this case the video covered it better.

And yeah, I feel like strain could be so much fun to roleplay, compared to spell slots.

Not sure who Raith Roguestar is, but the original source for these monsters (and more! a Pumpkin King boss with lair/legendary actions!) appears to be https://emberdm.tumblr.com/post/188729099266/medievil-pumpkins-dd-5e-monster-stats-for.