If you mean we becoming the "main" Patriarch like the Orthodox one, no, you can't, because Docetist has no religious head. Autocephaly =/= Religious head. Eventually most (reformed) religions will get creatable heads when they reach a position of power (like... 50% of religious authority for example), except Populist ones for obvious reasons (Our model for Populist religions is usually the Cathars, can you imagine a Cathar Pope? Neither do I). But that's at the bottom of a very long list.
The "Unite the fragmented faiths" decision was deprecated because basically the Reform mechanics made it obsolete for most religions, or didn't make much sense for LI.