Library management was equivalent on the footprint side for v4. Only difference was that the official lib still was using the github plugin so the github repo structure was insane as a result (and you got updates without user control by default)
I am however still confused why a version 4 project would require a version 5 file. Something fishy is going on here and just pulling in the file will just hide that fact instead of being a proper fix.
Seems like we had the Pitch prefix already shortened in that particular repo (so the old footprint repos were worse than i remembered).
Which means the user just needs to add that library to their setup via the library wizard (directly from gitlab or follow the local installation guide in How can i install a specific version of the footprint library?). So new assumption: this is a group project and there are differences in library setup as the different students are on different platforms or one student did some steps that @Giovanni did not follow (v4 is too long back so i can not remember if i needed to do something to get all footprint libs. I just know that by default only a small fraction of symbol libs was available.)