I like having thorough lists and I am curious what as many as possible are regardless of political silliness or differences in using financial systems.
My guess is the crypto one is presearch, but the others I have no idea.
Sounds like two were excluded for having a far-right focus, one for crypto payments, and the rest for being small/simple proof-of-concepts
That said, I would also be interested in what engines in particular were excluded, with a small blurb as to why it wasn't included.
I absolutely hate when people claim to be providing a "complete" list of something and then skip things because 'reasons'.