A bit late but I hope you can still make some changes to Anatolia they aren't that many that need it...
-The Marmara Islands (at the time called Prokonisos from the Greek word proika meaning wealth and nisos meaning island, since many of the royal family had mansions in the Islands and would spend a lot of time there) shown to be part of the location of Bandirma and subsequently the Karasid Beylik. However the Islands would remain a Roman possession until the middle of the 15th century (they were probably conquered along with Constantinople).
Thus I suggest to make them a separate location in order for them to be a part of Byzantium without the rest of the Bamdirma location which wasn't and shouldn't be depicted as such (or if the islands are very small to become its own location you can give those islands to the Biga or Rhaedestus location as they were part of Byzantium at the time).
-And finally Biga (or Pegai in Greek). Interestingly Biga would fall (1364) to the Ottoman's much later than the rest of the Byzantine holdings in the Marmara sea. Biga itself was a small outmost rather than a town at the time and it was probably for that reason that the Ottoman's didn't conquer it sooner, seeing it as insignificant.
Now Biga as a location is extremely big and it reaches a lot further south and west than it should, the Romans had a very tenuous hold of biga itself (let alone so much of it's surroundings) so the location itself should be as small as possible to depict that. So below I have drawn with red the area that should be taken off of biga and given to the two bordering locations of Can and Lapsecki for a more accurate border between the Karasids (and later Ottoman's) and the Byzantines.
Above is the location of the town (notice how the town doesn't reach that much southwest as the location would suggest).
There is also this weird salient that makes the border between the Ottomans and Germyanids look really off, that makes the Eskisehir location to be almost surrounded by the Germyanids.
I think a more curved border would look better, taking that red painted area and giving it to the Ottoman's, something like this perhaps?