By the way, where can I find information on nodes.dat formats v2&v3 ?
I mean, besides RoutingZone.cpp .....
I don't know of any other information source but source code.
However, you might have a look at src/utils/fileview/KadFiles.cpp : DecodeNodesDat(). The code there should be fairly simple and straightforward to reproduce in any script.
Should you have any questions I'd gladly provide you the answers.