% of total count when rows are not exclusive, and there's a pivot

[COG]

I’m trying to build a visualisation to show the number of customers that have enabled a certain feature.

There are two dimensions - feature type (set as a dimension/row - about 100 values) and customer type (set as pivot - about 5 values). The measure is count of customers. 

I’d like to show the percentage of each customer type that has a feature enabled. 

When I use % of column, Looker counts each customer multiple times as it sums the count for each feature type and doesn’t dedupe.

Is there a way to implement this?