I don't buy this. Gmail allows you to sort/select using other parameters. This would simply be another search param. Note that I'm not disputing the fact that

I don't buy this. Gmail allows you to sort/select using other parameters. This would simply be another search param. Note that I'm not disputing the fact that this may be an expensive operation. But I am able to go in through IMAP and issue the equivalent instructions, sort by size in client, then issue IMAP delete/purge requests, the net result is the same so why not enable this.