Hi,
I've built a trunnion fourth and platter fifth axis and use it no trouble.
Mach4 can handle six coordinated axes without difficulty.
Homing a rotary axis, be it four or five, requires something like 10ar second accuracy, so using the servo to home is advantageous, but not actually required.
I home my axes with a probing jig and homing script and can home both the trunnion and the platter to with 10 arc second in about 30 seconds to a minute, without
relying on index homing.
What Mach4 does not have is reverse kinematics (RK) which in turn means you must set the stock material is the exact same location as the CAM generated the code.
Its a little bit of a pain, but it works fine.
If Mach4Hobby had kinematics then you can place the stock material anywhere with the envelope and the kinematics will adjust the tool path in such a manner to correct the
difference between the 'assumed machine center, as seen by CAM' and the actual machine center.
Craig