It didn't show the XR Hands subsystem because at the time I didn't have the ml mrtk3 fork and I was using the standard MRTK3.0.
I got that sample project and built it and it worked even in that unity version (I had tried the mrtk3 fork sample but didn't realize there were different branches of it). I then went back and fought with mine again, eventually getting it to pretty much match exactly and was still having issues and I don't know how I stumbled upon it but I did realize that the MLInput had different binding properties for the LeftHand > Position even though it was in the package and the package was correct.
So I did a Reimport All.
Apparently that was my issue the entire time. 
Thanks for all the assistance on this. Sorry it ended up being something so silly. I guess the Unity Library got tripped up when I switched the version of the MLSDK or the ML MRTK3 package. Oof.