If it works for you great, but you probably aren't getting the results you think you are within the weld. You are going from a process that was meant to be Constant Voltage to a "make work" constant current wire feed. A voltage sensing suitcase like a Miller or a Lincoln requires a third wire to clamp on to sense the voltage to properly feed the wire. If you are welding up 3/4" in single pass, then you will likely burn your gun up quickly because it has a limited duty cycle as well and you are ignoring that but more than that, the weld won't be strong as a multipass weld. Your wire feed mechanism likely isn't intended for a hundred percent feed time either and will burn up because it is assumed that the normal weld circuit overheat would protect it.

For our welders and the "suit case" industry, it really doesn't make sense because it's easy enough to run an extension cord for our welders that is heavy enough to run the unit properly any where a cable can go. We can offer that kind of unit as one of our factories produce it, but it doesn't make good marketing sense since the industry is headed toward inverters and a simple plug. That's sort of like us considering producing High Freq boxes for engine drive welders...not a lot of point and it isn't our market.