How use IBP WEIGHTED AVERAGE with Aggregation

Dear Experts,

I need to aggregate a calculated Key Figure KF1@WKLOCPRODCUST with IBP_WEIGHTEDAVG(). KF1 must be used in another key figure KF3 calculation on @WKLOCCUST planning level. Therefore, I use following calculation.

KF1@REQUEST=IBP_WEIGHTEDAVG(KF1@WKLOCPRODCUST, KF2@WKLOCPRODCUST, ''CALCULATEDNUMERATOR'')

KF1@WKLOCCUST = SUM(KF1@WKLOCPRODCUST)

KF3 calculation with KF1:

KF3@REQUEST = SUM (KF3@WKLOCCUST)

KF3@WKLOCCUST = KF1@WKLOCCUST * KF4@WKLOCCUST

With these calculations KF1 is displayed Weighted Average on Excel planning view, but SUM aggregated in the KF3 calculation.

How can I aggregate KF1 from @WKLOCPRODCUST to @WKLOCCUST with IBP_WEIGHTEDAVG()?