I find that fluorescent lights and LED nigh lights hold ambient just fine. Ambient temps have a long range if we look at the bitter ends (I avoid the ends) but 75 at the low side and 88 at the high. (I use 78-85 personally) This is a big target so high precision is not needed. In the summer I often run fluorescent lights for a few hours in the morning and afternoon with LED (deep blue for royals has lower visibility than red) over night in the dead cold of winter I run the led 24/7 and fluorescent 12 on 12 off. The fl lights run a surface temp of 100º or so and led in the 90s. This when the warm air circulates hold 10-15º over the ambient air temps. I add insulation and get 3-5 on top again. This keeps the 70-60º room inside an acceptable range. I find my ambient temps change during the day They start low and gain to the afternoon and drop again over night. My winter low is about 78-9 and highs are 84-5 I build one degree every hour and a half or so.

I have RHPs (two actually) One is used as they were designed in an arboreal set up with vertical gradients and tall ceilings. The other is in a 12 inch enclosure I used it as a test for ages (empty of just snake) and now I use it to hold the hot spot. With light weight hides it make next to no difference to ambients at all. Good thing too. The surface is often 160º to hold a 90º hot spot and if it added substantially to the ambient temps It would cook the snake (10-15% of 160 is 16-24º over room temps. I know way over simplified but to illustrate the point)

RHPs have and are being used in rooms kept at 80º or close to it and it is also clear that the ambient air temps are not in the 90s under these conditions. It either heats the air or it does not, if they do the excitedly hot operational temps (hotter than my UTH get) would make them unsafe in a serious way. UTH gain 3-5% in my tests about the same as the RHP as they are effectively the same. Adding heavy mass that is heated will clearly add some more but how much I cannot guess as I have not experimented with it.