BP Heating Trouble

[Bogertophis]

I recently bought a juvenile BP and am super excited to bring him home. Currently the breeder is holding onto him until I have the heating and humidity figured out in his enclosure. I currently have a problem. Before setting up the enclosure I had decided on side-tank heating. For reference, this is a 40gal glass enclosure and I’m currently using a 30-40gal zilla heatmat. Now thinking everything would go well, I threw away the four little nubs that are meant to go under the tank if you use UTH. Though, lo-and-behold my warm side barely reaches 30C even though the thermostat is set to 50C while also using a heat lamp. The cold side averages about 22C. Both sides fall to around 22C (Warm) and 20C (Cold) each night and I can’t reposition the heat mat without risking a fire. (Yes ik 40 gal is big for a juvenile, I have it very cluttered I assure you.)

Does anyone have any tips? Is it safe to try and continuously raise the heat mat until it suits my needs? Is there something I can use as an alternative to the little nubbies so I may reposition the heatmat? Should I cave and just buy a stronger lamp or new heatmat?

Heat mats for snakes belong under the tank- heat rises, so installing one on the side is very inefficient. Be careful about removing it to re-install it- damage can occur that renders it inoperable.
They must also be temperature-regulated for safety- preferably with a thermostat, or with a rheostat at the very least (& be aware that some types of UTH will just go off if dimmed with a rheostat).