However, it would seem to me that you would need a specific variable
speed drive for each tool, that you would not want to walk to the corner
to adjust the speed. That could get pricy.

A lot (if not all) VFD's can use remote speed setting. A 2 or 3 core flex to
a potentiometer will do the job. This can then be taken to the machine in
use on it's long lead. Remote stop/start/reverse controls are also
incorporated into many VFD's.
As a thought, I suppose that a VFD could be coupled to a lathe Digital Read
Out to set the speed according to the diameter of the work. That way, the
linear cutting speed is kept constant as the workpiece diameter is reduced.
Very handy for facing cuts. Lots of you will no doubt tell be that this is
already the case somewhere.

John