Hi jock
Yes, I'm going to send some of the files in Kindle format for a couple of people to read. ( I only have Kindle for PC so I don't know if that's representative.)
Anyway, I should get a clear idea of what it's like displayed on their devices as they are very tech-minded.
As for publishers, I get increasingly depressed about the things I hear. Almost no chance of getting it read, not even by a good agent. The mistake I made was by building a cathedral first instead of a few nicely made beach huts. But I will try.