List element - Gen Sal 'Last Updated'

Hi folks,

I have had a weird request come through to me asking for a list of constituents based on when their 'Gen Sal' was last pushed/updated.  Essentially, our membership manager wants to help use this for data maintenance purposes whenever a constituent changes membership categories, as a way to filter out those where Gen Sal was recently pushed/updated.

So essentially the list would look for everyone who had a membership category change in the last month, but did not have Gen Sal pushed/updated in the last month....hoping that makes sense.

Anyone know if having a list element based on when salutations were last generated is possible? And if so, how I would go about it? Thanks!