wired the five lane entrance signals to a red wire, and strung it to poles to the two faux-chain signal as you called it.
kept the output signals normal. the faux-chain signals are set to RED > 4 close signal.
seems to be working so far. when it goes green they go to an open lane. haven't seen one jam up yet

might just ditch chain signals all together till they get fixed/reworked.
cheers