Personally, the truth is that it depends on the fish. Your fish could come out of its shell tmro or in 2 years. you really never know, i think your best bet is to slowly add what you want and simply closely monitor the situation, it is the only true solution, given that there is nobody who can guarantee you when your dovii is gonna flip. Just have a tank ready or at the very least a divider and keep a close eye.
A 180 imo is way to small for a full grown male dovii anyways. So since I'm assuming you'll upgrade down the road for him, Id add a mix of other cichlids and when he snaps move him to his new larger tank.
Yeah I will be upgrading to either a 300 or a 240 in the long run but I think I'm gonna try a couple of Midas and a group of cons and I'll grow out a group of 3-4 dovii to try get a male
Considering how well Midas and Red Devils can take care of themselves and they are some of my favorites. I can tell you if that Dovi decides that he is claiming that tank I believe over time he will brutalized them to death. Dove's can be fierce. I have raised them and Midas for years.