I downloaded the eQSL AG Member List Dated file containing the date of the last upload/import for each member. The raw file had 141,441 records. After filtering for US call signs the number was down to a little over 32,000 including almost 15,000 that had no activity in at least 10 years. Of the total calls only about 12,000 had uploaded or imported QSO's into eQSL since 1/1/2020 and only about 8,000 had uploaded or imported QSO's into eQSL since the beginning of 2021.
I suggest using the eQSL dated member file and adding an option to allow specifying a Last Activity Date threshold (i.e. filter for eQSL AG who had activity within the current year or last 6 months or since a specific date). There's no point in filtering for eQSL AG ops if the majority of them haven't been active in eQSL in many years and you cannot weed out the inactive members. .
It was discussed about the possibility of adding a Wanted County feature to aid in county hunting. That would only be valuable if the suggested Last Activity Date function was included as CQ currently only accepts QSO confirmations for the County award via eQSL AG and cards. Chasing down an AG op with a QTH in a wanted county who hasn't uploaded in a decade is a waste of time .
To handle this for right now I've created a database of all AG members with activity since 1/1/2021, retrieved their county from a master file of 770,000 US ham calls and compared the result to a list of the counties I still need. I then import the results in a comma delimited text file into the Wanted Call signs function. Seems to work well.
73 Pat N6PAT