[dmix]

Right you can turn off getting any messages entirely and deregister your phone from their network. I believe what I was remembering was you can't swap out the primary SMS receiving app like you can on Android. Unless something changed. Not everyone like's to live in a security bubble w/o phone access, even the security minded.

[isx726552]

There is a switch in the Settings app to disable iMessage and just use SMS. This is an option for the built in messaging app, no need to “swap” or install another app.

[dmix]

So basically still using iMessage software just for SMS? I guess this could provide some better sense of security given the parsers are the main issue.

[prox]

No the “message” app just becomes an sms texting app. I think it’s indicated by a color change.

[samtheprogram]

You can disable iMessage and still get plain SMS and MMS. The app is called Messages, and Apple's version of RCS is called iMessage.

But you are correct that you cannot switch to a different SMS/MMS app.