Phantom grips aren't great in non-LSD transmissions, but in a VLSD they are a decent addition.
Something tells me it needs to be installed tighter. You want the strongest springs, and you want to use a vise/press to squeeze it enough to install it. You shouldn't be installing it by hand or anything. Also you'll want to make sure to use fluid that's not too slippery or anything. Redline MT-90 boi.