quick update, i got another UTH, this one covers half of the tub. and i stuck the other one on the top of the tub, hooked to the same reostat.
i havent insulated anything, and with this change, (so far... still have to let it test for 12-24 more hours) im sitting at 93F base layer substrate on half the tank with the top layer at 90F, and the ambient temp on the other side at 78F. with 61% humidity(outside room temp is 70F, and 37% humidity)
so, thats a lot closer to the target than before, ill play around with wrapping towels on it to see if i can tweak it the rest of the way.
SO, dont throw away your old UTH, might be able to use it like i am. ill post the results after 12, and 24 hours of running like this.