I wrote a blog post that's a fairly detailed how-to on conducting usability testing for free software: https://samuelhewitt.com/blog/2019-08-27-how-to-run-a-usability-test-on-free-software-linux
@snwh I wish non-free software makers would do usability tests too! (Most don't.)
@snwh Many of them used to, but not so much anymore. It's a "move fast and break things" mentality now.