Disclaimer:The comment below didn't representative my real personal politic view.
Many muslim refugees back Ottoman.They're revanchism and hard find new position in new home,likely become longterm problem.OTL example is repatriation Greek after Greco-Turkish War largely become supporter of KKE...
It's remind me that OTL France investor in Russia before WW1 likely become non-exist,maybe most of can come to Ottoman renew traditional Ottman-France relationship.
Some addition of block strait:if Ottoman didn't do it,Britain will "help" you do it.
Even IOTL Ottoman has achieve own revenge:Block of Dardanelles nail the coffin of Tsar Nicholas.In the situation of three Emperors alliance,the pressure from ground force in Balkan increase signally.But thank Bulgaria,Ottoman has a shield to both beat Austria and Russia(of course,don't need take...
The final reconciliation of Sunni and Shia in 1.0 make too optimistic,but directionality was right.Maybe Caliph can have more initiative to do something.
May be should edit map.By the way,it's see that TTL Ottoman's hardware(like railway)and software(like constitution)both have nearly 10 years earlier.It's fair enough now.Particularly 10 years effect will more significant in far east.
Edit: I will miss the Belgian
There were many aspects affect by Meiji Restoration.One of them was make first time East Asia become more significance than West Asia in world.For now ITTL,this trend still going on.
Yes,the ethnic quetion of Ottoman can't avoid,only can make alleviate like in 2.0,but potential of Ottoman also...
With the spirit of 2.0,look it's hardly paint Ottoman colour in Nejd.And after mass territory lost,Oil will become more important resource for Ottoman,Should find some way maximize exploitation right in Arab peninsula.
I guess one of the Emperor is
I also want to talk something after mention Yaqub Beg.Ottoman not only nominally suzerain of Yettishar Khanate,they also make maximal effort to send material support like advisors.Although Pan-Turkish won't become mainstream ideology ITTL Ottoman,there're still naturelly that Ottoman extend...
Very impressive,because I know it's come from OTL.The reason of failure of Second Constitutional Era worth a long paper,I only say some own thought.The Constitution,make clear status of every Ottomans.Buffer no exist and crash between different ethnic group more likely happen.
My suggest is...
In a more wider view,the affect of lost Ottoman Europe has already metion in update so not repeat here.There're also few good thing turn internal:even Abdul Hamid did his best, still need somebody responsible for failure .It will make Young Turks Revolution ITTL.
Edit:with personal brain...