if the manufacturers have a driver that will blow right out of the box by connecting them to motors with a lower amp rating than stock config then they are selling a crappy product.
I think you misunderstand. If you connect a 1 A motor to a driver set up to deliver 7 A, you might blow the MOTOR. That would be your fault.
If you connect a driver to a motor which has been mis-wired to present zero inductance, then you might blow the driver. That too would be your fault.
I know the gecko didn't get hot. I was holding it in my hand. My stepper DID get hot though.
Holding the Gecko in your hand when it should have been bolted down to a heatsink would also be your fault.
It may be that in this case yo have merely 'warmed' the motor and the Gecko has survived.
If the supply amperage is the problem then I should be able to take a second gecko and hook it up with the proper amp setting and it should perform beautifully, right?
NOT if you have the motor mis-wired.
What I found interesting is the manual says if I hook it up to a common on terminal 10 it can be 3.3vdc, 5.5vdc or gnd. I find it odd that it can be any of the three without additional jumper settings.
Yeah, that is OK. It just means they have a 'smart' front end or interface. Quite reasonable.
Building a CNC actually requires some engineering and electronic skills. It is not something you can easily do by yourself without those skills - despite what vendors might claim.
Cheers
Roger