I think your tooling is awesome. I am using the [url=https://meetcircle.com/circle/]Circle[/url] hotspot to track and limit time for my kids. The MacBook in the house gets used by all the family and I would like to be able to set the MAC address uniquely for each kid when they login. Your tooling is so close to being able to do that. Looks like one more property of who is logged in would support it. I'm sure the solution would work with either LaunchDaemons or LaunchAgents.
Interested? I think you could sell a whole bunch of these to parents who purchased [url=https://meetcircle.com/circle/]Circle[/url] . Let me know.
now that i think about it,
Im don't think a user variable is needed.
why don't you just set login rules for WiFiSpoof on each of your child's user accounts?
Each user on your computer would have their own WiFiSpoof preferences and rules, and this would give you the result you're after