They make buttons with gaskets you could sort out. The USB is trickier...
Discussion
What I find frustrating with USB is that all the cords are different--while the plug itself is standard, the plastic surrounding the plug varies wildly...
And the RAK module I have has the USB-C ending almost flush with the board itself--so you really need to account for the plastic on the cord for your enclosure (although I may try to work around that at some point).
Even so, with USB-C it'll never be completely waterproof...what these things really need is wireless charging! 😃
(And the same with trying to attach a solar panel--no good way I can see to waterproof this elegantly--may just have to put it into a Pelican case or something similar)
Clear pelican for solar?
Yeah, that's certainly a possibility, yet I've never really liked doing that kind of thing (always seems less than elegant)...
Thinking more about this--and I believe I may have a solution...
I could put "threads" on the end of the case where the USB port is, and then have a screw on cover for that area (that you could seal with an o-ring).
That'd maintain access to the charging port, while offering a weatherproof design for when the device is in use...
Will take some re-engineering of my current case design, but betting I could make that work...hmmmm...