"merge work/recording" edits should offer editors the option to either allow all existing author and performer relationships to be aggregated under the target, or to disallow this in order to keep the target relationships intact as the case may be. (the default should probably be the latter.) this will save editors the bother of having to repeatedly prune the targets (be they works/recordings or whatever) of incorrect/improper/redundant (but differently classified) relationships that might potentially be imported with each merge.

this option might apply to artists/releases/release groups as well. please disregard if already suggested, thks.