Corrections in the Caucus? It means giving up Georgian and Armenian land and I don’t see the Russians wanting to give up much of anything, especially when protecting Christians from being massacred was their excuse for their influence in the Ottoman Empire for the past half a century. I also feel they would not want the the Ottomans in, at least without getting concessions for themselves. Think like how the Allies against Napoleon near the end did not want Saxony to join in as the Prussians wanted to annex them entirely.
I also feel that Bulgaria and Romania cannot be guaranteed to join, as they were up in the air during WWI in which direction they would fall. Really, where is Bulgaria going to gain land if the Serbians keep refusing to give them any of Macedonia? The Bulgarians did not trust the Entente for the promises they tried to make that they knew would not be honored. They also offered the Bulgarians part of Ottoman Thrace, but in this world they cannot even offer that. Hell, IOTL the Ottomans gave land wrapping around their old capital to the Bulgarians, but that was in order to get the Bulgarians much closer to joining their alliance, as well as to have German and Austrian munitions sent to Gallipoli to protect their current capital. Also, you are going to have issues with Young Turks and the pro-German members of the navy, army, and business class perhaps not going along with the Sublime Porte if they feel that this will simply end up with the Russians, Italians, French, and British which kept picking off parts of their edges also trying to buy up or take for cheap German funded railroads.
Hmmm, doing something with Labania might be interesting, actually. Bit of a trade to get some islands back from Greece for Turkey in exchange for South Epirus. Or if the Greeks and Italians both end up in the Central Powers, the Bulgarians and Turks now have plenty of common ground for targets.
https://en.m.wikipedia.org/wiki/Bulgarian–Ottoman_convention_(1915)