ErleRobotics is dead, is there any chance to use ArduCopter 4.0.3 on PxfMini?

Hardware Linux
2

PXFMini should be very similar to this.

This should work.
You need to compile ardupilot from source code using:

make pxfmini-rover

the output is a file you need to copy to the RPIZero PXFMini and run it.
it should work.