Whenever the FA Community Sheild is, the Challenge Cup Final should be the weekend before.
The double header for the semi is a great idea, put that in late June; keep Magic in late May but don’t make it an EXTRA game (if we don’t make it an extra game it’ll give us an extra free week in the season), make it a home or away fixture for two teams and play the same fixture the year after (but reverse who’s home fixture it is) and then after two years you can change who plays who but make it the same for two years again with AvB in Year1 and BvA in Year2.
Mid-season international game in the USA should be the weekend after Magic. That gives fans who’ve spent a fortune at Magic a week off so don’t have to keep shelling money out.
Then the Super 8s or Play-offs or whenever structure we have will be an uninterrupted run later in the season to the GF.