[Spinball]

I have my own XBL Gamercard functionality which, in specific forums (just the Xbox ones), the user's avatar or gamercard will be displayed depending on a choice they make in their CP options page.
(I have the system create a narrower version of the gamercard which fits into postbit_legacy without forcing the cell width wider. I use an iFrame which calls an external script because I don't know how to code using the new plugin system).
The way I update the gamercards is to make a check only when the gamercard needs to be displayed. I.e. a users' post is displayed. Then it looks to see if the card has been updated in the last 24 hours, and if it hasn't, it updates it right away.
Maybe your system could do a full update once a week at a specified time -2am, say.
And then update as needed like my system does.
I would alter my system to use the info from your tables if your mod was working ok on our board.