On my opinion it`s doable but a bit dangerous because like for example an 80 watt laser module will be placed at the back of the machine and stationary because it`s impossible or even more dangerous to let the CNC arm carry the module, so the laser module at the back then use a 3 mirror to redirect the laser beam onto the arm itself, so basically the only load on the CNC arm is only a mirror but not just an ordinary mirror, a special kind of laser mirror for reflecting (metal gold plated) hi watt laser beams, then convert the Z axis on the table so that the table itself that is movable, you cant let the Z axis move the spindle side with mirror or else the beam will now be offset and it`s a disaster, so ya it`s doable but risky.