Great to have you back! Looking forward to this as always, and love the detailed blog!
For the echolot confirmation - I’d always be tempted to make the warning diegetic, rather than breaking immersion - whether it be a crew member asking for confirmation or some other in-world function, but I think your instincts are right that it needs something.
Do let us know when/if you need beta testers, I’d be happy to help root out bugs or problems when you feel the game is complete enough.
Take care!