Concerns about my new BP - Please help!

[Coluber42]

First off, you're going to have a lot of folks telling you the 40 gallon tank is too big. That is true if it doesn't have sufficient clutter in it. Large areas of open floor space are not good; fake or real foliage, tubes (paper towel rolls are good for small snakes), lots of hides, etc, will all help fill the space. It's completely possible to make a 40 gallon tank work well for a small snake, but you have to provide lots of visual cover and reassuringly solid objects for the snake to move around between. Open floor plans might be nice for humans who like to entertain, but not for baby snakes.
It may also help to wrap cardboad or paper around three sides of the tank so he feels more private. However, IMO you should not take away any of the stuff that's in there now or re-arrange it, just add more stuff if you need to. That's so that even if strange new things get added, the old familiar stuff is still there. It takes them longer than you think to settle into a new environment, and if everything in the environment changes, that's basically a new environment.

Next, your cool side is a bit too cool; it should be more like 80-ish. Snakes need heat to digest, and they often won't eat if they aren't warm enough to digest a meal. The fact that his favorite spot is basically as close to the heat source as he can get makes it sound like the rest of his cage is probably too cool. As the weather changes, you may need an additional heat source or more insulation to keep the rest of the cage warmer. How are you measuring temperatures in other parts of the cage? Even if your thermometer has only one or two probe locations, you can use a temp gun to check surface temperatures in other locations. If the surface inside a hide is 70, it's probably a decent assumption that the ambient temperature there is also 70.
If you're going to cover three sides of the tank for privacy anyway, you might as well do it with insulating foam to help retain heat. You can also put a piece of insulating foam (wrapped in foil preferably, for safety in case it gets too close to the CHE accidentally) over the screen of the tank lid, everywhere except where the CHE is. That will retain heat and also humidity. Depending on how you're measuring humidity and where, it's possible that it's actually quite a bit lower than 55% in some places, especially in the warmer parts of the cage. And if you raise the temperature by insulating the cage, that will lower the % humidity by definition even if nothing else changes. So you might need to add deeper substrate or a larger water bowl to help with humidity too once you get your temperatures a bit higher.

Next, you don't need to move him to feed. That's not helpful or necessary. But one thing you can try - since you have a small bin that you were using to feed anyway, cut a hole in the lid of that bin and put it inside the larger tank and leave it there. Now it's another additional hide with a different kind of entrance. You can even make it into a humid hide by filling it partway with damp coco husk, sphagnum moss, etc.