I was interested in using Andy's FabISP stick because I already have quite a few cables to carry around so avoiding another cable is a big plus, especially because most of my devices are now USB-C.
I starteded milling with the ShopBot while the Modela was in use. However, when I used the default settings, the cut speed was way too fast and led to poor cut quality and probably increased tool wear which should be avoided. Furthermore, the Andy's FabISP board had a trace spacing that was too narrow for FabModules to create a 1/64" toolpath. However, I didn't realize this until it was too late and soldering had begun.
The second try was much more successful. I slowed the speed down to 5 mm/s and lied to fab modules specifying the 1/64" (0.39mm) tool diameter as 0.33mm. This allowed fab modules to route the more narrow trace.
After soldering all the parts on (including the jumpers) I tried to program the board. As noted by others, the FR1 board is less thick than the standard USB device thickness so solder was added for mechanical strength and increased thickness. However, this wasn't enough so I added five vinyl sheets from the vinyl cutter to the bottom and the board fit into the USB port nicely.