try to disable the increase timing precision of the mainloop of the GUI vvvv instance. so it will free its time slice as soon as its frame is done. does this help?
does the GUI instance also have a DX renderer? try setting it to immediately so it does not sync/wait for anything.
Just a guess if we can have GUI patch as separate thread or something, some special priority node u add to patch so it refershes faster or draggin boxes in it don’t slows ur output mmmm?