Yes, you can probably run the motor with a lower current.
Stepper motors require pulses of current. The electrical characteristics (inductance and back-emf) mean that it takes time for the current to rise after a pulse is "switched on". For a given supply voltage at some speed the current will never reach its max because the pulse is too short. However, at slow speeds - with longer pulses - it will reach the max.
Stepper motors draw their full current even when stationary.
A specialized stepper driver can drive the motor with a very high voltage so that the current rises quickly to the full permitted level even in short pulses. It also has the ability to prevent the current rising beyond the set limit so that the high voltage does not damage the motor.
The h-bridge drivers like the Velleman do not have the ability to limit the current so they cannot be used with a high voltage power supply.
Separately, you cannot limit the current by using a low-current power supply. The motor will try to draw its full current and may damage the power supply. Or the power supply voltage will fall and won't be sufficient.
Did I understand you correctly if I think what you are saying is that if I am getting the motor to run on the Vallman shield regardless what power supply I’m using then the motor has to have drawn its full amp (2.8 + 2.8 Amps)? If so then that is more than the shield is rated to handle and it is much more than my power supply says it can deliver. Could I be damaging the shield or motor by doing this?
And if not, then I don’t understand why you say that the current cannot be limited by using a low-current supply, because unless the motor right now is drawing 2.8+2.8A then I am doing that right now am I not?
And if I buy a new big easy driver, will it automatically limit the current to 2amps per coil on my stepper so that it will be safe to use? Or could a too powerful motor destroy the driver? I did notice that when the big easy driver was working it got very hot, but maybe that’s normal since they sell heat sinks and so on for them.