I have built control box extensions for the cover panel when the VFD did not fit. I had some phenolic impregnated CE board that I used, but just about anything will work. Probably want to extend it to around 8". You could probably dump the big transformer for a more compact 24VDC unit if you choose to go that route and plan to use smaller control relays. Surprised you do not have enough room on the front panel, did a recent build on a 1440 lathe, and was able to fit everything in, but the speed readout was put up above under the DRO. I like thisposition, as it is easily seen when operating the machine. You can combine functions, so the power on light can be in the E-Stop or use a lighted Jog.Have been using a joystick for individuals that want forward/reverse jog feature.
One awesome machine, will be a monster once you add the VFD. A perfect combination.