Yeah, pretty much any printer board can be made to work with mpcnc. However if you don’t go with an officially recommended board, then you have to sort out the configuration with relatively less support. There are lots of knowledgeable and helpful folks here that can help you get it working though. IMHO setup is not that hard to do, but I am somewhat experienced with nc machines, circuit design, coding, milling (on bridgeports etc), and editing config files. For a total beginner, sorting things like pinouts from schematics and config files, or setting up features like autosquare might be too tall challenge to figure out the first time around with cnc. Since you seem to have experience from printing enough to be comfy configuring an octopus pro, you likely already have the skills needed to get it working. However, keep in mind if you aren’t versed in cnc, there are already a lot of things to learn that have nothing to do with the controller.
That’s why Ryan’s design and prepackaged firmware setups are so valuable to those beginning in CNC… takes a lot of the time/learning curve out of the way, leaving you to focus on non-print related cnc stuff like CAM, fixturing, machine alignment, probing, feedrates, cutting strategies, etc. I did personally start right off using GRBL on my primo for various reasons, and now I’m running fluidnc on a 6-pack board (so pretty far from “standard”). It certainly is superior when it comes to laser use at least, and it works great with my favorite sender bCNC (which afaik is the only software I’ve seen that can do leveling correction properly… this is critical for PCB milling). So “Mapping your own adventure” with mpcnc does have it’s place if’n you know what you’re doing and where you want to go with it. You have to expect more days of mulling over code and schematics before it’s cutting if you do.
edit: BTW, lol bigger is generally better for mills. It’s just that with all the plastic etc, there’s only so much horsepower you can put into a bit before things get way out of shape. At least with a watercooled spindle (65 or 80mm), you can drop RPM a ton vs the usual trim routers and maintain torque… exactly what you want for cutting alum. You can probably even stick to 2-flute.