Wow, very interested. Not at all in love with my inreach explorer... It's "ok" and does what I need it to but as with (in my experience) most Garmin products, it's a bit "clunky". The topo mapping is functional but honestly worlds away from smartphone capabilities. To be fair they are two very different platforms.
So basically if I'm going to be using my phone anyway, an "easy" messenging and sos commutator makes a lot of sense... Downsides for me are that my phone isn't waterproof, and the battery life is far shorter than the inreach which is essentially just primarily tracking my and pinging a location every ten minutes, with occasional screen time for topo map reference.
Then there is the issue of keeping two separate electronics charged and operational, two things to fail vs one, etc.
Still, I really like this idea. Very interested to hear your experience.
The monthly plan is FAR more reasonable, too! I'm going to do some more digging on this. Thanks for posting!!