When oXygen project files are commited in SCM, and many developers create various scenarios, merging xpr file can be a nightmare.
Editions Lefebvre-Sarrut has released a maven plugin that keep your project file entries sorted, and simplifies the merge - you still have to resolve conflicts, but that's much easier.
https://github.com/ELSGestion/oxygen-pjt-beautifier-maven-plugin
Best,
Christophe