Really my only complaint about the SO3 (I just have the regular small one): it won’t fit a 2x2’ sheet of MDF from the hardware store. You need to cut about 1-2" off to get it fit. Which pretty much means you’re going to be cutting stock to fit.
As other people have said, work-holding and dust management are the two massive things you will need to do to really start making use of your SO3, I looked at what other people had done ahead of time, and kinda copied/stole where I needed to. I’ve added them into my github library:
The dust-shoe just requires some material to be stapled around the outside. I have almost unlimited quantities of this rubberized nylon material, I made a skirt, and then cut it into strips after attaching it. Then stuffed my vaccum cleaner into the other hole. It helps an amazing amount, it probably knocks 95% of the dust out, there is still about 5% remaining.
The spoilboard I created is just another part that goes on top of the one the machine ships with, I didn’t want to drill a bunch of holes in mine, just enough holes to hold my other board on.
There are threaded inserts you can buy, home depot sells them, they’re kinda terrible, but they do work, however for some god aweful reason they are only available in 20mm length, but the max thickness of MDF you can easily find is like .73" (20mm is ~.78" so they always stick out, so you either have to grind them flat, or layer boards up, really annoying (not C3D’s fault tho).
The big thing, if all this is new to you, is learn how to think of everything as a “toolchain” meaning each process is done by a specific tool, in a specific order, so
Design -> Toolpath -> Controller interface -> routing
Is kinda the basic of the process, and each is a specific skill.