Some stuff just isn't covered in the PPL exams (at least not the Canadian one) and the particular instructor might miss them. Besides, tiny little airplanes don't have EGT gauges. I had to tune mine entirely by ear. Getting peak power is a bit of an art in such a case.
Will a small engine stay happy at altitude running on full rich? Of course there will be power loss and increased fuel consumption, but I don't know how unhappy the engine will get. (I assume with a nick like IO540, you know them a lot better than I do.)