I'm [I][U]not interested[U][I] in using my tab to make calls; only to send texts via the native in-built messaging app. I don't want to use other Android apps, just the stock messaging. I am able to do this to great success on Sprint. Sprint is able to go into the backend system and apply conditional call forwarding. Not the case with Tmo.
My main purpose is to NOT miss calls from people who may decide to call via reply to text as that's what appears as my callback number when it's not.
Thanks so much to everyone for your input.