Ok, and now I've played extensively on Plvs Vltra as it stands as both the Ottoman Empire and Venice. I'd say the overall game experience is extremely different than on MyMap, and without necessarily having anticipated this ahead of time, much more historically sensible. There's some philosophical question on exactly what we're symbolizing in historical-spatial terms for each province, and what degree of historical exactness involved in terms of what spaces occasionally may have shifted from one temporal power to another at moments need to be sacrificed to accomplish a sort of map which itself would lead to the most historical game-play mechanics. Overall at this point I think that the Plvs Vltra map is actually superior to MyMap in terms of both Balkans and Italian gameplay, with the smaller number of Balkans provinces actually enhancing the game experience. Separating Cattaro from Zeta is still plausible, and adding Syrmia also would not be especially implausible, but two provinces rather than three for Bosnia and two rather than four Croatian provinces, the positioning of Macedonia, and several other issues definitely lead to more historically accurate game scenarios than in MyMap.
Urbino seems like it would also be a good addition. I actually appreciate the existence of the Massa province in Italy, as it adds some sense of Italy being a "big" place (if not geographically, definitely politically) at that time. I'd also note that after having mostly played on MyMap since FTG was released, that having two provinces for Sicily as on the present Plvs Vltra map does add some depth and (contrary to above where fewer Balkans provinces made for a more generally historically-plausible game) historical plausibility to the Mediterranean game; that is, Sicily can become too tempting of a target for the Ottomans to hold when it's just a single province -- taken as two provinces, even if you play as the Ottomans and win a big war against Spain and take the whole island, it's more much more sensible at that point to release it as a vassal. Sicily was held by Muslims at early points, but for the Ottomans to be able to hold it as easily as in MyMap might not be especially plausible.
I would as a sort of experimental project enjoy seeing an extremely detailed FTG map which attempts to add as many provinces as possible, taking into account maximum historical depth (I mean, that could involve even separating Salonika from the Macedonian hinterland, etc) after region limits are lifted, while still maintaining a game balance and general historical plausibility, but the present mod appears to not be that project.