I actually like the idea of an interconnect card. It depends how much you plan to add on the machine, mine had a manual Z-axis which I added a motor (hence the Z-focus option in T2Laser) and you probably want to keep limit switches etc.
The Eleks Mana CNC has 3-axis and connectors for all these features, the Cronos Maker is similar and also supports an offline controller (run from SD card, which is what I use on my CNC so the laptop doesn't get covered in debris). I dislike that the Cronos uses an integrated SMT microcontroller rather than a Nano but it's been very reliable. There's others which combine the best features of each, I think one is the Developower (maybe see if you can find one on aliexpress or ebay).