Edent, 
I saw so many people with folding phones today that it has given me total tech envy.
My OnePlus 5T is approaching 6 years old. Has a replacement battery and flashed with Lineage in order to get modern features.
I'm fully aboard the Reduce, Reuse, Recycle train. So I'll wait until it gives up the ghost and then buy a 2nd hand fold.
Looks like only the Pixel has 3rd party ROMs. So that's another good excuse to wait.
But I want a new toy!