@b4n all tags files probably need to be UTF-8 since the symbols we generate in real-time are from the "always UTF-8" Scintilla buffer, that way symbols from both will match.
The basic ctags tab separated format should be ok with UTF-8 IIUC. (so long as we are sure its UTF-8 :)
IIUC uctags is also developing a JSON format but its not finalised yet.
And I'm certainly not supporting tagmanager format, its only plus is that we can modify it.