Try reducing light by 1 hour a day to help not stress them.
My thoughts are yo need all the light those two blurps can give. This is from a bestva blurple user. Without it I can see loose light small buds.
On the herming some plants readily herm for almost no reason. Others you can beat the hell out of do a 100% change of everything and it just makes them stronger. So I hope you can see the difficultly in answering that question.
As far as heat. I thought if I had a better idea of the layout I could maybe offer some help. Problem is without throwing money at them I’m at a loss for the moment. I understand money is tight and understandably so in this economy.
Sorry I can be no more help than this. Other than to say. Lose the tent altogether move them as close to the door of the room as possible and have a fan blowing between the lights and the canopy into the room. That will take direct heat off of the canopy. There is still going to be indirect heat but hopefully that will stay in the 80s or lower. At least anything less than 90 would be helpful.
Again on the herming. My gut says you will not have a problem. But there are no guarantees.