Possibly just symlinking it all over to MSYS $HOME?
I am definitely happy about being able to install tmux.
edit: just seems like I should ditch what I was doing in windows home, because git bash used the same home and I had everything there. ssh stuff, git config, inputrc, .vim, etc. But if I'm no longer using git bash, no need.
edit: sadly git runs very oddly in this. not sure what git bash is doing differently, but I'm comparing .64 seconds for a git status, versus over a minute with MSY2. weird.