The mini Rambo won’t accommodate the dual endstop configuration at all.
The Rambo only has 5 stepper drivers, and the dual endstop configuration uses all 5, leaving none available to run an extruder.
Basically, it is not easily possible to add the extruder to your existing dual endstop MPCNC.
It may be possible, but it would not be trivial. I don’t know how to do it, and a brief search didn’t turn up anything that looked helpful.
Sorry.
If you’re willing to sacrifice the dual endstops it would be easy.