Grbl is only 8 bit so be careful.
GrblHAL is 32 but…
I have a posting on two hardware solutions with the one based on the Teensy 4.1 being enough axis and switches to run a AvidCNC Pro series machine.
If you combine that interface with the Teknic motors then you can have a really tiny control box and run it from your phone.
I have been considering this as well as LinuxCNC. I personally would use LinuxCNC right now as the GrblHAL stuff isn’t as mature as I would like for a production system.
But give it time. Right now GrblHAL boasts everything Mach4 does out of the box. But I am not interested in being a beta tester.
See my thread “The Beginning of the End” for the links.