i am thinking of replacing my 2020 L Eco with a 2022 Limited. I wonder if this will result in more battery drain due to more sensors. Smart key sensor is only on the driver's door for L Eco. Limited has three times the sensors. i do not drive often. Thus there is more battery drain. This was a problem on my C which also had three sensors.
May not be a BHG. The cooling also runs to the exhaust pipes. That part of the system has been known to leak and become defective.
You are taking the wrong approach here. THIS is what you need to address, no matter what make or model car you have. The common solution is a battery tender. Note: If you don't have the C anymore you might want to change that in your profile.
If I understand your concerns correctly from how I read your post, I wouldn't worry about it, to much anyways. I haven't seen any reports here at PC about gen 4 (any trim / model) having 12 volt issues, yet. like they say YMMV