I definitely want it back, is the Crimea on Genoa's War/Settler Maps? It should be. Genoa held Caffa for 200 years, more time than any settlement on Sardinia. I think that in our game we always have Genoa settle Sardinia because we don't have A Republic of Pisa, Sardinia was mainly ruled by Pisa until Aragon took over. Genoa's actual conquests that were maintained Genoese for reasonable amounts of time were Corsica, the Crimea, a number of islands in the Aegean, and the foretress of Tabarka in Tunisia (and NW Sardinia for a short time). For the purposes of this mod, Sardinia should be in the requirement, but I have no idea where this UHV gets Milan, Marseille, and Crete from. Genoa never controlled either Milan or Marseille. Crete was controlled temporarily but that was mainly Venetian territory. Rhodes was also mainly Venetian.
If the UHV is too hard, let's remove the ahistorical part. I think a Genoese venture all the way to the Crimea would be a lot more fun and interesting than trying to build a small ahistorical land empire over the Duchy of Milan and Provence while running Merchant Republic. I can't stress enough that a historical trading empire over lands spread across two seas would be more exciting than ahistorically having to fight the French or Burgundians. That's what playing as the French or Burgundians is for.
How about this as a new UHV:
In x year, control 3 Mediterranean islands and the Crimea.
The 3 intended Mediterranean islands would be Corsica (guaranteed), Sardinia (also easy but Spain might take it), and an island in the Aegean sea such as Chios or Lesbos OR Rhodes (conflict with Byzantines, Ottomans). Sicily is always there for the unambitious player but I don't think it should be in the war/settler map as Genoa purely trading there, nothing more. The Crimea will be the hardest, but probably the most fun. IRL Genoa had more than a few trading colonies on the Black sea. It would be fun to see how much the player could carve out of Kiev and the Byzantine empire and how long they could hold against the Ottomans.
The year could be 1475, loss of Caffa to the Ottomans. 1500, that year rounded up, or 1566, loss of last territory East of Italy to the Ottomans.