Hi John,
This is a primitive method of displaying the data you want, but it should work.
In the SEPM, run a "Computer Status" log under the Monitors tab. Use Advanced settings and filter the report for "All Non-Windows" machines.
The resulting log does have an entry for every SAVFL machine that uses SAVFL Reporter. (These can be idnetified by their Version or Group Name.) One field returned is their definitions date.
Please update this thread with news if this works for you!