Hi And welcome to Connect, Also this may answer your questions also @frostbite as my wife is very slender also. She just had one inserted a few months ago and is doing great. She tells me it was a bit sore for a few days after but didn't need any pain meds except Tylenol. It was very quick procedure like 10 min and most likely (She's retired) go back to work right away .
Her phone is the device that gets the readings from the implant and so far nothing noticeable has been sent but there is a button you can push on you phone app to log something that feels unusual. She hasn't had to use it yet but either way everything the implant sees is recorded and sent via her phone. Hope that helps as for her being slender she did say at first during the implanting it brused her ribs a bit but doesn't even notice it now.
Blessings