I recommend before you make a change that you familiarize yourself with the debates within Orthodoxy and who they say are Schismatics.
On the one hand, you have the Greek Old Calendarists who severed communion with the Greek Church over the adoption of a New Calendar. The New Calendarists rightly condemned them as Schismatics for declaring the Greek Hierarchy deposed by the very fact of accepting a New Calendar. The Old Calendarists did not summon any bishops to a trial or deal with the issue in a canonical way at all and devolved into fanaticism, saying the New Calendarist Sacraments were invalid.
Now wait, if this is a schismatic act, then the Orthodox are self-condemned- for which Latin Bishop or Hierarchy did they canonically try in a court in order to condemn? When is the Papacy even first anathematized by NAME? 1583.
Moreover, in an Orthodox synod, you have the patriarch and his Metropolitans. Now, if the Metropolitans sever communion with the patriarch and declare him deposed without a trial are they Schismatics? Yes. Nikodemos of Athos talks about this in his commentary on the canons- no canonical penalty has any force unless a living council enacts it.
Again, what living council ever summoned and canonically tried and anathematized the Latins or the Pope? None.
As for Changes, just read about all the opinions of those who refused to accept the innovations of Gregory Palamas which are now standard Orthodoxy.
Why do the Orthodox always break up the reunion attempts first?
Schism. It won’t wash.