He is also a "Microsoft Regional Director". I thought that was a position at Microsoft, but after actually looking at it, it looks like you're correct.
HIBP can check passwords. Some password managers integrate with it, like Bitwarden. Troy Hunt, the person behind HIBP works at Microsoft is a Microsoft MVP.
Cryptpad has Forms. You can choose if users need to sign in. Looks like you don't even need an account to create one on their official instance. It's self-hostable too.
Unfortunately, Firefox doesn't even support HDR on Windows