You could conformal coat electronics if they aren't already. Would provide some moisture protection.

Potting is more extreme, were use special epoxy to encapsulate the electronics. Not many flash light manufacturers do it.

US based Pflexpro takes Convoy flashlights made in China, and one of the mods they do is to pot the electronics.

https://www.pflexpro.com/Potted-Flashlight-and-P60-Drop-In-s/1841.htm

PS Not associated nor a customer (I'm in EU) of Pflexpro, but they seem pretty well thought of in the flashlight communities online.