In previous patches, joining the HRE prevents you from rising above duchy rank. But it seems that in 1.30 being the HREmperor automatically places you at empire rank anyway. So are there any disadvantages to joining the HRE at all?
Not being able to be emperor (wrong religion or gov type). Also you cannot dismantile if a part of HRE
Not being able to be emperor (wrong religion or gov type). Also you cannot dismantile if a part of HRE and dismantile is a nice move and easy for countries like hussite Bohemia or Poland or Denmrk and so on
If your capital is in the HRE you cannot (easily) move it to Japan and become Shogun.
How so? Are they not mechanically very similar? Sure HRE vassals don't fight internal wars.HRE vassal swarm beats Japanese vassal swarm, I think.
You absolutely can dismantle the HRE as a member, you just can't be emperor and do so. Its common to dismantle the HRE as Prussia.
The main disadvantage is you are fixed to Duchy if not emperor, though if you become a elector (Hungary takes this from Bohemia through their mission tree), you can be a kingdom.