The servers with the features I want are of the 25565 variety, and the iPad won't connect to them. I've observed that my iPad can connect to servers that default to serving port 19132 (which I think is UDP-based) but not to servers that default to serving on port 25565 (which I think is TCP-based). So is it still true today that MCPE is 'fundamentally different' from the PC version? But I read that in 2015 or so the two systems converged in some way. People used to refer to the iOS games as 'Minecraft Pocket Edition' or MCPE, because it was a fundamentally different codebase from the java version.
I'm trying to set up a Minecraft server to connect to my iPad client, and am confused about the state of the world in 2020 because I get the impression things have changed over the years, and it's hard to know what information I read online is still true.