I will be using LinuxCNC which IS capable of handling closed loop feedback. From what I've read, it's just a case of using a servo profile and editing the parameters to match the motor and encoder.

I've never used a stepper driven CNC, but have worked in engineering for 22 years. The idea of controlling a precision drive system without any feedback seems to go against basic engineering principles as you never know the exact state or position of the machine. I guess that's the trade off from doing it "on the cheap"?