Thanks for your reply. I feel like I 90% get the concept of federalisation, and it’s very interesting. Just from a purely user experience point of view (because this is what was asked), I’ve already had several times where I’ve ended up on the “wrong” instance without realising it. I guess it partly takes getting used to. My experience has been more positive than negative overall though.
A relatively small thing: the 500-comment viewing limit for normal accounts. So many times on Reddit I’ve been put off engaging with posts with 500+ comments knowing that nobody would see it. It’s stupid because comments are just text and unless the software design is absolutely terrible then simple text comments shouldn’t take up bandwidth at all.