Simply put if a borg is flashed (non-functional) they should be immune to flashes while they are offline/non-functional. From an RP side the idea that you can flash an already offline camera seems rather stupid. From a balance side, it makes chain stunning borgs actually require skill, and gives the borg chances to fight back. Cyborgs already rapidly lose modules from damage (rendering them useless), the self-repair is slow, and if damaged to a certain extent requires a human to repair (replace armor plating), and of course, the all mighty robo console can lockdown or blow up a cyborg.