tim-bezhashvyly/magmi-grouped-price-plugin — pull request #1 by sickelap (2013-05-08 09:11:01+00:00)
Title: Clean group price update

Maybe it's just my use case, but I can't think of it differently. IMO when you are updating group prices and there is no price specified for certain group, then that group should not be in the product configuration.