Engine rooms can get very hot and are full of plumbing. Heat and water are both bad for electronics.
That said, PO installed a Sterling smart regulator in the engine room and it's been doing just fine there. That's however just a smart regulator (and potted against moisture), an A2B charger is likely to be much more sensitive to high temperatures and moisture (and same applies for solar chargers - some may be IPx5 rated, but still need to dissipate heat). Here in Greece even in June our engine room regularly gets above 40°C (I have a blower fan I'll be fitting this summer). Not ideal for most chargers if you look in the spec sheet.
Overly bright LEDs are easily toned down with some tape or dark nailpolish.