Hi,
demo is still demo. If you have an active motion controller Mach4 will run for about 5-6 minutes before it needs to be reset.
If you use the Sim plugin it will run without limit, being a simulator it will not run a physical machine. The Modbus plugin is to my knowledge fully functional
and so you could use it to control a spindle or any Modbus device without limit with demo.
If you want to control a machine for longer periods of time you'll have to buy a licence.
I personally think $200 (perpetual) for the Hobby version for up to five PCs/ machines is good value. If I had the extra I would now buy the Industrial variant,
the main added capability that I am aware of and would really like is functionality of all six out-of-band axes. At the current time Mach4Hobby is limited to one out-of-band
axis and its always a spindle.
Craig