Can this formula be transformed to only count unique values within each sheet?

[Lebene]

Hello!

I have learned a new formula today
=SUMPRODUCT(COUNTIF(INDIRECT("'"&SheetNames&"'!"&"w2:w500"),F2)) Formula source: How To Count Items Across Multiple Worksheets In Excel

I want the formula to only count the criteria (F2) once in each cell.

I saw this but I don't know how to combine them, or even if that's legal. Excel formula: Count unique values in a range with COUNTIF | Exceljet