Recently I had a requirement to sort a dataset in a random order. So I have a suggestion to make an option to SEQNUM keyword, eq.: SEQNUM,6,ZD,RANDOM. This example should generate a random number between 1 and 999999 (I leave the details to the developers...)
This way I can sort on the SEQNUM in pass 2, and athieve a random order of records in the dataset.