I didn't know there was a disagreement about whether or not the Macedonians were Slavs. Old Macedonian (closely related to Old Church Slavonic is a proto Slavic language (my memory is not clear but it could be that Old Macedonian is THE proto Slavic language or even one of the second generation...
I work with a Monarchist page on Facebook and we try to keep the fake royals off the page and, when necessary, exposing their fraud.
Recently I came across a fellow presenting himself as Prince Cosimo, Head of the Royal House of Macedonia. Frankly, I know almost nothing about the Royal history...