From my (limited) experience Chinese routers seem to originate from one and the same design but are manufactured (even faked) at many places. A guy here bought one (2400 x 1500 mm) and I went to make the initial set up and bring it to running condition. Has a similar pendant with an USB flash drive socket. Because there was not even an user manual with it and the man had pressed on "Factory default" on the pendant I had to measure the ball screw step and the drivers' microstep settings in order to make it move again. So I had a fair look at the internals and I think a Mach3 conversion must be easy. One only needs a good parallel port controller to provide "Dir", "Step" and "Enable" signals to the stepper drivers and to accommodate the inputs - limit switches, touch probe, etc. Spindle spin up delay and speed management may be a bit more complicated but the VFD inverters usually have more than one way of remote control.