Hiding UI without breaking trackables

I've made this neat custom GUI using trackables and destructables, and i want to hide the normal UI while players are using it for aesthetic reasons.
Only problem seems to be, that using "Letterbox mode" in GUI or the Showinterface() native in JASS disables all trackables while used.
For JASS i would use the following natives:

            call ShowInterface(false, 0)
            call EnableUserControl(true)

to hide the UI but view the cursor, and the cursor works with everything else except the trackables.
Any help to get?
I prefer not using custom fade filters, even though it is an option, since it takes up map space (and i'm not evens ure if it overlaps the UI).