Obviously having the temperature right is the best, but I’d personally prefer a temperature problem to be a tad low than high. Too much heat is more likely to cause problems than too little, though extremes of either are not really good. I’ve had eggs under a broody get real cold when she went back to the wrong nest yet 11 out of 11 hatched.
Don’t let what I just said panic you though. How much damage might have been done depends on what happened to the temperature inside those eggs. All you were measuring was air temperature. It takes a lot longer for the temperature inside the eggs to go up much. There is an excellent chance that temperature spike caused no damage. You are probably right to worry most about those tiny Serama eggs, but even for them two hours doesn’t sound too bad.
It’s aggravating when things like that happen. I was not real happy with that broody when I found her on the wrong nest and those eggs felt really really cold. Yet 11 out of 11 hatched. Those eggs are often a lot tougher than people think.
I don’t know what stage they are in but you might try candling in a few days to see if they are still developing ion schedule.
I wish you luck!
