MuseScore 3 should use different file extension from MuseScore 2

I strongly support this idea, and every day more and more threads about compatibility problems are answered the same way: "two different layout engines, but no prob, keep both software and continue the work on V2 scores with V2 if you prefer to avoid the conversion work."
This shows clearly enough that that the default extensions MUST be different, the major advantage being to keep different file associations at OS level, at the choice of the user. And that wouldn't prevent to open V2 extension with V3, even by default. So it is not at all too late to intrdoduce this change. Unfortunately the MuseScores Lords have decided otherwise, and once they have an opinion it is extremely difficult to have them change their mind.