They've been saying this for how many years..?

You go ahead and keep working on it, Signal.

Yea, too little too late.

When they removed support for SMS integration and justified by saying "engineering costs", my trust in them sank to zero.

Sorry, there's trivial engineering costs to use SMS - so little there have been numerous free SMS apps since at least 2010 - good ones - because the OS handles it, not your app.

Pretty much all of my Signal contacts were persuaded (by me) to use the service way back when. It was like pulling teeth.

Getting them ALL to switch to SimpleX was surprisingly easy. Some might still use Signal, but that doesn't affect me so I've been able to uninstall it.