At least CalyxOS, DivestOS offer Android 13 builds for FP4 (and obviously LineageOS, but it doesn’t have OTA updates, afaik)

Well, IPx5 is technically water resistant for water jets and up to 12.5 liters per minute. I think that sounds enough to be used it rain. I also saw some reviews of other devices that even IPx4 is fine in rain.

If that were true that it wouldn’t be just a side note because it would render the whole Bitwarden product useless. It’d pretty much mean that they are not encrypting passwords at all, so even worse than infamous LastPass. But as the other comment pointed out, it’s pretty much not like that.