Heterogeneous membership in decumulation only CDC plans

Decumulation-only CDC plans provide a retirement income to their members.
They do this primarily by pooling longevity risk among the members. Previous results in this research programme established that decumulation-only CDC plans should be open to new members, to ensure sufficient longevity risk pooling.
When new members are the same as each other, then the results suggest that only about 100 of them need to join each year to get the majority of the longevity risk pooling benefits.
However, it is much more realistic to assume that members join with different amounts of money.
In that case, how many of them are needed to get enough longevity risk pooling?
The research results on this question are presented in the webinar present by Professor Catherine Donnelly.