Every time I open a project, I get 1 or 2 of these requests for every project built. These files need to be under SCM control and should not be modified unless absolutely necessary.
These request block other operations and make your tool more difficult to use.
If the files get changed and the file is locked, the file could be saved under a different name (.project.bak) for comparison after the session. If the saved changes are needed, the file could be checked out and replaced with the new file rather than having the changes lost.
Bill