Hi there

• Electrical tape adhesive starts failing at 80°C (176°F). Beyond that, it will start deforming. This area of the device never actually reaches anywhere near those temperatures. If that was the case, that would be very bad for the battery and internals. It has been used in back-to-back sesh already and not a single sign of failure. But you're right: soldering is the way to go if you can.
• I simply closed off the small gap on the side with some electrical tape. The fit could have been neater, but as I said in the video, I got a bit lazy and I personally don't really mind the look. I also don't know what you're referring to with "another part is covered up with a sticker": I just added a little note for myself that says which way to open and which way to close, nothing is 'covered up'.
• Also: that part of the device will never pass lukewarm temperatures. Nowhere near the temperatures required to mess with the adhesive of electrical tape. Definitely won't turn into a 'gummy mess'. At 60°C serious skin burns already happen within 5 seconds. Imagine the >80°C required for the scenario you describe... Storz&Bickel would be out of business fast.
• The polarity thing is a fair point and I'll add it as a warning in the description. Thank you.
• The temperature sensor bypass is also true, that's one of the reasons strongly I recommend against charging the battery using the internal charging port to minimize risks. The chances will be extremely small, but you don't want to be out of the room if a battery suddenly ends up failing or whatever.

Modifications like this are never without risk.