For each cluster with at least one member of length >= 500:
If only the representative has length >= 500 (or there are no non-representative members):
duplicate the representative
else:
add the highest pLDDT non-representative member with length >= 500
52196254 representatives originally
duplicate 3946647 representatives
add 2961293 cluster members
Final length: 59104194
Note that the original cluster representatives are chosen by highest pLDDT irrespective of length (in AFDB50).