you dont have to plug, you could even remove it altogether if you want. your greddy is controling things now. is the top hose on the stocker just a dummy hose or does it actually lead to somewhere? Id be optimising your hoses to, as you said that pink one is deff too long and all over the place.
do you know how to adjust your ebc? you might have to adjust the settings. are you after 12 psi or just 8?