Hi RCaffin,

Most multi-meters are good for many things, like checking for continuity, but they collect and display data too slowly for things like measuring peak current draw. Fast accelerations may require peak torque (peak current draw) for a period of time measured in milliseconds. These peaks are often too fast for the meter to display. Using an oscilloscope is the only way to be sure that you are measuring true peak requirements.

Running (4) NEMA23 motors with (1) IPC-5 should be no problem.

Running (4) 1 stack NEMA34 motors (e.g. 3411) with (1) IPC-5 "should" be no problem (but needs to be tested to be sure)

Running (4) 4 stack NEMA34 motors (e.g. 3441) will probably require two power supplies (but it depends on your accelerations, friction, duty cycle, etc.)