The multichociemodding is not the problem, the huge database tasks like expanding minister/leader dbs is the real nightmare.
I have to agree.
I personally dread having to work on ministers/leaders, be it in research, or in events when I need to wake/sleep.
Thankfully Kaiser Franz is a godsend for AAR.
Other nuisances I have are testing (every minute spent on testing is time lost from development) and players going way ahistorical breaking event chains while expecting existing historical events to work (well, mostly trying to account for ahistorical stuff in triggers, who doesn't like playing ahistorical?)
I don't think it is that far fetched to see a major mod or two merged into Vanilla by this time next year.