Garmin has webinars every couple months (I forgot how I signed up for these) on various topics around the Inreach. I'd sign up for those as you can ask the presenters (Garmin employees) most any question on topic.
I signed up (via my Garmin portal account) for additional coverage insurance as it is reasonable at $50/year and it might cover items that my employer based insurance does not. IIRC, the additional insurance offered by Garmin is through a third party company.
I will say, like most insurance companies, I fully expect to have to fight with them on coverage should I need their service, especially if it a large amount like a medivac, etc.
Good luck,
Eddie