The code base I am using has specific enhanemments other than M48/G29/G30 I need to use. My understanding is that it's g30 is better in that it takes only a few passes to converge, so I was also hoping to use it.

Thanks for the help, Roxy. I guess I'll just have to work it out what is going on with what I have.

I sure would like to know why they rewrote your m48 code for the latest Marlin pull, though. As it is, there is a lot of code in marlin_main.cpp for this stuff when it seems it could be unified into something much simpler.