Alright, I think I found an answer. Thanks to @jgstew 's post: Need Tuple Inspectors, No easy way to convert a plural set of objects into a tuple
I learned about the “tuple string items” inspector. Then it was a matter of turning each tuple of the plural result into a single string, and then concatenating the strings. So now my relevance looks like this:
(if exists (tuple string items of it) whose
(tuple string item 0 of it ... and tuple string item 1 of it ... and tuple string item 2 of it ... and tuple string item 3 of it ...)
then "LICENSED: ACCT #" else
if exists (tuple string items of it) whose
(tuple string item 0 of it ... and tuple string item 1 of it ... and tuple string item 2 of it ... and tuple string item 3 of it ...)
then "LICENSED: ACCT #" else
etc.....
)
of
(concatenation ", " of
( "( " & Item0Relevance as string & ", " &
Item1Relevance as string & ", " &
Item2Relevance as string & ", " &
Item3Relevance as string & " )") of files of folder "...")