I'd set the grommets in first:
Use a cheap string at kind of high on the tension range.
Hit hard against a wall or backboard for a half hour.
Cut out the cheap string.
#1 above, taking your best guess for the new tensions.
Dunlop MuscleWeave 200G 95, Cyberflash 1.25/Hexy Fiber 17 @48/53, thinking of trying 47/51, Alpha Pioneer DC+ dropweight