Hm :\
Well, just curious: how do you install Xposed with GravityBox? Preferably link me to a thread, because I don't see any thread on these forums related to Xposed.
It's pretty simple, you download and install xposed installer and then, using that app, you install framework to your phone. Reboot, and then you download gravitybox for jb from xposed installer(it has sort of download centre that allows you to easily find and download modules), install it, activate module in xposed installer and reboot your phone. Then you can modifxy whatever you want with that gravitybox app, most things dont require reboot to apply changes, but some of them do. FYI, you can also try xblast tools module if you don't like gravitybox for changing screen off effect.
Links: xdaforums.com/xposed/framework-xposed-rom-modding-modifying-t1574401
xdaforums.com/xposed/modules/app-gravitybox-v2-9-1-tweak-box-android-t2316070
Don't be scared with warnings that gravitybox needs aosp roms to work, it works fine on stock xperia rom.