Ability to do adds first during a loader job (rather than deletes

The Grouper Loader processes group membership deletes before it processes group membership adds. For large groups (for which adds and deletes require more time & processing power), this can cause up to several hours of 'service flickering,' which is essentially users losing membership to a group that provides a service for the period of time it takes the delete and then the add to process. It might be better to process the adds before the deletes so that this service flicker doesn't take place.

We believe this is the spot in the code where the Grouper Loader chooses to process deletes before adds:

 https://github.com/Internet2/grouper/blob/GROUPER_2_5_BRANCH/grouper/src/grouper/edu/internet2/middleware/grouper/app/loader/GrouperLoaderType.java#L3321

Would it be possible to allow us to configure this so that we could tell the Grouper Loader to process the membership adds before the deletes? We understand that there are some situations in which it's better for deletes to occur before adds, but it would be nice to be able to have the choice to configure the loader to do adds before deletes.