I remember there was some discussion in the past regarding lights/fixtures with 2 different circuits and being able to tag both circuits. I might have missed this as a possible solution, but I came across a work around recently.
As you know if you use a light fixture or electrical fixture tag that displays the circuit and the deivce has 2 connectors you are unable to get both circuits to show up. However, a simple fix to this is instead of tagging the device you tag wires. Draw wires coming off of each connector that are as small as possible(if the wire is short enough a arrow head will not show up.) You can then hide that dot/short line of wire in the symbology of the family and you can tag it. This would work well for lighting that have emergency and normal power coming from 2 panels.
I am posting this because if anyone can think of reasons why this wouldn't work or why it would not be a good workflow I would like to hear it. Just because it works for 1 situation doesn't mean it would work for all.