Depends on whom you ask..
Yes our Mach3 does home properly when we press the "Ref All Home" button, and it will set the machine coords to "0" properly. We did the required correct setups in Mach3's config->Ports And Pins and config->Homing/Limits. And our mill delivers referencing signals (actually limit switch signals). I can go with you thru the details. I can't help you with Sheetcam.