I've been drooling over the Titan, but the lack of an AOSP-derived ROM for it is an absolute blocker. I do not trust manufacturer's firmware one iota, no matter what, and this is only getting worse over time.

The best thing Unihertz could do in my mind would be to dump a bunch of support and money at LineageOS and get their phones supported. Especially the one with the DMR walkie talkie; the lack of third-party support for those is crippling them.