@simsa04 Ah, ok, I meant that, even using the same protocol (AP), different implementations can (and do) create incompatibilities.
For example, the mentioned patch to fix Misskey federation changes how LRDD and Webfinger work in Gnusocial, making it more compatible with Misskey.
Besides the oficial AP docs, (too technical for me), I'm afraid I haven't seen any blog post explaining all this; technical info about Gs is scarce.