Hey there.
What a lot of people do (including myself) is put a digital temp probe inside the tank so that you can set the thermostat a little higher and still have the temp that you want on the substrate/glass. I don't see a huge issue with how you did it the only concern I would have is in the off chance that the probe gets knocked loose or pulled off of the glass than your UTH is going to heat up to the full capacity. I would be concerned that because of the high humidity needed for BPs, that moisture could get under the glue and lift the adhesive.
Not saying the way that you did it is wrong - everyone has their own methods of husbandry, and if its working for you than that's awesome. I'm just playing the devils advocate.
Cheers!