I don't have a dog in this fight.
1. I have arranged things via google text before when I was without a hobby phone.
2. I've carried a hobby phone, but then you need to explain why you have one. "Oh yeah, when I broke my Galaxy II on that trip, I grabbed a pay as you go until work sent me a new phone"
3. My cell phone has software on it that allows my work to track what I'm doing with their cell phone. So I don't use Apps, Gvoice, or visit websites with it.
4. Calls from better hotels list the phone number dialed on the bill.
I'm a lazy hobbyist, If I decide to hobby on a trip I may try google-voice text only first, I may call from the hotel and "edit" the bill, or I may drop by a store and get a burner phone.
... but I will follow what ever rules a verified lady has established.