Sorry I don't have any additional ideas beyond what you've tried. I just wanted to add that you won't be able to pass your next smog test with the bulb out or with the light on. I don't think you have a choice other than to keep on pursuing it.
Has anyone stuck an old fashioned sniffer in the tailpipe to see if there are any emissions measurements obviously out of spec?
Experience is something you don't get until just after you need it.