Apply Last Sales Activity to Transactions

I really like the addition of "Last Sales Activity" to customer records which was added in the last release and I'd like to find a way to do something similar on the transaction level.

I've tried setting up searches on activities and/or messages but the problem I have is there seems to be no way to only look at the date/time of the most recent message or activity.

I'm also open to other methods to get where I'm going. I'm trying to search for all open estimates which don't have any activity/phone call/message logged since the day the estimate was created. I could use the LSA for the customer, but our larger customers have multiple estimates out there at the same time so the LSA may or may not have anything to do with that specific estimate.