I didn't read OP or 90% of this thread, but here's the bottom line: Zenos needs to just be done as he hasn't been relevant since Stormblood. The final fight with him was pretty good, though.

Zenos was the weakest part of this expansion by far; even his tenuous relevance wasn't utilized much at all. That being said, it's over now, and we can move on.

Forge ahead!