A new wall which would block all newtonian gravity passing through it.
The difference to the gravity wall we have is that if you make a strong gravity field and then put some particles behind a thin sheet of that wall then the particles will just fly off like normal.
This could be helpful for weapons which use newtonian gravity for effects or acceleration.
Lets say you have 2 hollow squares each one made of one of the two gravity walls and they both have a maximum power GPMP ball inside them.
The original would neutralize the GPMP completely.
The new one would prevent it from affecting things from outside the square but not on the inside with it.
(I DONT PUNCTUATION WELL)
Simply blocking gravity should actually be fairly easy. in fact, it IS easy. It's easier than the area block walls.