QKSMS has a better interface than Simple SMS Messenger, but it's unmaintained, and for me, it had the same or worse problems with MMS than Simple SMS has.

It sure looks unmaintained!

Here are my problems with Simple SMS that are fixed in QKSMS:

1) Long delay updating conversation after receiving a message (>5s).

2) Date sorting broken (old messages appearing at top of queue for no reason).

3) "Failed to send" sms users experience is bad (still testing on qk).

4) MMS sender ID almost always wrong (all messages in group MMS appear to be from the same person until you examine details).

5) Sending MMS with attachment/image always fails without verbose error (still testing qk)

This is pretty abysmal. Do I use the unmaintained app that fixes 3-5 of these issues, or the apparently actively developed one with all the warts? I guess this is the state of basic phone functionality in vendor-free, google-free android.

If only Signal hadn't dropped support for SMS/MMS... It was like a major selling point!

Not only did it completely ruin my SMS experience when this happened, it cratered my signal use as well. From my perspective, it was a really misguided choice.

I admit I passed over trying this for whatever reason. I'll try it now and report back.