Sea Frogs underwater housings for mirrorless cameras

I recently got a Sea Frogs Salted Line underwater housing for a Sony a6500.

I’m setting things up, seeing what else I need, looking and lens compatibility, etc, etc, etc.

What I’m wondering is if anyone here has any experience with these housings, and things I should be aware of or pay special attention to?

Also, if anyone has recommendations on a good lens to use in one for a Sony a6500?

(to be clear, I have a decent array of lenses as it stands, but shooting underwater is a whole different beast, and my past experience with is is with a GoPro, so quite a bit different.)

@joe_fish - any input?