Tracking on cellular connection

Hi,

I got a new 67i and have the Enabled plan. I did some hikes with my phone connected over BT. It seems that on routes where I got cellular connection for the most part of the trip I used none or only a few tracking credits. Where I was out of cell range I spent more credits. It seems that while messages are always sent by satellite, tracking works both via inReach and cellular, if available. Could someone confirm that?

I have Livetrack enabled. Would it work differently on Mapshare?

If I'm in cellular range will I be charged for message replies and reaction I receive when the other party is using a Garmin Messanger app to reply while I'm back in cellular range when the reply is being sent?