Follow me for a second:
Why do you have a Unihertz phone? Because you value small phones
What other phone will you buy after this one? Another Unihertz, because you value small phones
What will happen if Unihertz starts supporting Lineage? You will keep your current phone
Why would Unihertz put effort into that?
Yours is a noble campaign and I wish you all the luck.
That said, I must admit I myself would have been using Jellies exclusively since long ago if they were supported in Lineage.
btw: it's a shame the community has no way to pay Lineage towards supporting specific phone models (yeah, I guess I could search for like-minded people and arrange a deal directly with one or more developers, but that would be a too much extra hassle).