Recently I tested rolling back SBP by following SBP readme guide, it surprises that the rolling back action will un-install all the SBP you ever installed. Which means that it will bring the database back to the base version without SBP. This has confirmed by SAP oracle colleague.
So the only way to revert back to the old SBP is to roll back SBP, then install the old SBP again.
We have to be careful before deciding to revert back to the old SBP. Because the old SBP package may not be available from SAP website.
By the way I tested in 11g database version (but I believe all the versions should be affected).