Wan port spoof mac address auto changer/generator?

[tastyratz]

Is there a way to the spoof wan mac address on a pfsense box automatically on intervals? (every x days, or x gb download transfer which is preferred, etc)

Some ISP's have a traffic watch that is bound to connected device eth port mac address and not to the modem itself. I was hoping to stay off Santa's naughty list by staying a step ahead.

I found this page with a perl script: https://calomel.org/mac_random.html
Not sure how to really trigger it though. Maybe a cron that polls incoming traffic on the hour to see if it goes above X?

Any tips? Any reason to suspect the linked script being incompatible?

Thanks!