So for anyone wondering, there seems to be an active community still around this mod. AFAICT the current effort is best accessed here: https://github.com/nullprofile/krpc
In the releases you can find krpc recompiles for current versions of KSP, and under actions you can grab the CI builds of the current development which will also include new features found in stock, including those added by @artwhaley and mentioned by them in the post above.
I'm a bit allergic to hanging out on discord and apparently this is where people are so I don't know why no one officially adopted krpc or at least posts here from time to time, and I hope I don't step on anyone's toes by posting, but I'm very happy that krpc lives on and thought I'd share.