Isolating Split Variants from VDS

I have a VDS file in AoU and want to split multiallelics using hail.vds.split_multi and then write the variants that were multiallelic to a txt file.

I saw that the split_multi command on VDS files also created that row field. I can count the number of split multiallelics using the following:


Do you all have advice on filtering by those split alleles and writing them to a txt file in an efficient manner? On trying to launch it, it looks like it would be an expensive operation.