The criticism is that better privacy can be achieved by not saving data, it is a good criticism but I don’t know how legit it is because I don’t know if credit card payments can be processed without saving the data (i would assume yes, if tokenized)

As far as i know, display link requires software not available on the pixel, so you must be using display port and confusing both. Display port supports all the things you said

Boost in Google Play

It’s not open source, though

I use boost, to me it was the best reddit client and when it came to lemmy all others felt incomplete so I jumped over ASAP and I haven’t missed anything.