Can you please elaborate, why?
monitor debugging requires that you include a "foreign object" i.e. the monitor in your code. That has absolutotally nothing to do with "learning the intricaciers of the '51".

But being on high end, AD's ADuCs have integrated quasiICE facilities, too.
I know, and use the SILabs chips, and have never stated that they are the only ones with "built in ICE". That the compiler supplied with the AduC chips do not have any documentation is another story. At least the Keil eval, whatever its limitations, is documented.

Erik