One thing I do not want in Felunyx is a huge “supported” list that really means only “someone can probably install it.”
D-108 makes the boundary more honest: other DEs and WMs can be installed, but project-validated integration, configuration, compatibility, and support belong to the official profiles.
That is not a lock. It simply separates freedom from guarantees. Users can still change the system; Felunyx can still say precisely where testing and maintenance time was actually spent.
Compatible does not mean validated. It is a small sentence, but it prevents a lot of accidental promises — especially in a rolling distro where the surrounding ecosystem keeps changing.