Put the jumppower back to the level before the nerf (yes even with only one jumpjet). But make the jumpjet fuel dependend from the count of jumpjets you built in your mech.
Maybe two seconds power for one jumpjet. Only refills if not flying.
Heavies could jump over small gap or an little hill, but not more. Jumpjets on scouts would be worth the weight again.
Think about a Spider-V jumping over the tunnel on Frozen City. Or jump behind a mech, fire, and jump away. With many jumpjets you don't have to wait for the refill.
Just my 2 cents.
PS: I'm not native speaking english, not even my first foreign language, so be patient
