The saving of some settings per "globbed file", might be tricky, and I something I wouldn't do (my feeling : to much added complexity).
The behavior has changed from your implementation. In your implementation the glob file was special, you could change the compiler options but they were not saved. This was confusing for me on the first use...
In my implementation the glob files are like regular files. They are added to the project, like if you add a file with Project->Add file, just automatically, no special handling, no additional complexity.
This comes with the specialty, that your project file gets changed every time the globs change...