How to add custom primitive data to PCG Biome Core generated ISM

I can add a custom primitive data on a foliage instance static mesh and it works fine as shown in this picture

However on pcg biome generated ISM whenever I click the plus sign to add the primitive custom attribute it automatically regenerates and loses that value. Is there a way to keep that value or add it to the pcg biome core defaults or make something in blueprints that re-adds that value after it regenerates?

Every time I click the plus sign to add tree wind strength it regenerates and loose that value.

Did you find a solution?