UDF with Family table that includes parameters

I have a UDF of some pipe flanges with a family table. The family table drives 5 dimensions (no problem there) and one parameter (a HOLE_AMT parameter to calculate my hole pattern dimensions.

The problem is, if I insert 2 different sized flanges using the UDF, both UDF groups end up being driven by a single assembly-level HOLE_AMT parameter. So if I insert a flange with a 4-hole pattern first, then insert a flange with an 8 hole pattern, the one that's supposed to have 8 holes ends up having 4, as it's driven by the HOLE_AMT parameter from the first flange.

Thanks in advance for the help.