A paid Mysudo will do both SMS and encrypted in same app.

It will encrypt if the other uses the free or paid version of MySudo.  Hard to get people to move to that. 

Other non SMS options mentioned Briar (tor based), SimpleX (signal+relay based), OxChat (nostr based) and Keet (bittorrent based) all seem good options. Dont forget Molly as a Signal replacement.

Ultimately I had to grab a cheap 2nd phone for one needed app that GrapheneOS wouldnt run. So I SMS off that with my $8/month plan.  I dont carry it during the day and tell people if they need quicker response to message me via another means.