I use the truecaller sms client, and that still let’s you select multiple convos.
I use truecaller sms as my primary sms client, but before I install TCsms I install Evolve sms app, as that lats you back up and restore sms msg to most of the big clouds.
So I download /restore all my messages with evolve sms, then download truecaller sms for default duties.
When it’s time to get a new phone (or periodically) I’ll fire back up evolve sms to back up the new sms I wish to keep.
Evolve is a very good messaging app in its own right. If I recall, it went slow, may be fixed now. I used it primary for years.
I think the truecaller sms spam filter is why i stay
But evolve may do it for you with needed TCsms
I may of had a bit of pop, so my texting may be worse, or even better. Lol