I’ve been the guy hovering by the strip before and it’s way more awkward than just saying “mind if I grab this slot?” Usually someone just nods and that’s it. Two nights goes fast, so I’d rather ask once than sit there watching my phone die.
Mine actually seemed to quit doing much once I crammed the shelves too tight. I still keep it in there but I moved it to the door shelf where there’s a little breathing room, and that made a bigger difference for me than leaving it buried. If space is tight I’d just pick a spot near the front and not fuss over it.
Half full is fine in my experience, but I noticed the cycle seems to do more for the bottle itself than the water when there’s not much in there. Mine sat with maybe a quarter of water overnight once and the inside still smelled clean the next morning. So for travel where you’re mostly worried about the bottle getting funky, that’s plenty.