This is marvellous news. Any hints on how to convert them to the combined rabbit holes? I'm assuming it would be equally simple, such as just putting in "Sims3.Gameplay.Objects.RabbitHoles.BookstoreAndSpa", or something similar.
EDIT: So, yes, this works, and is rather simple to do so. I converted the Annex RH into a school/stadium combo simply by looking up the appropriate code (Sims3.Gameplay.Objects.RabbitHoles.ComboSchoolStadium) but they act as default replacements and when I sent my sim to get a job at the new stadium, it came up as "BlahBlah needs to be at the Schmidt Memorial Stadium and Annex..." Any ideas on how to change the names of the rabbitholes, and have them appear as separate packages? This is my first foray into anything beyond simply playing the game, if it wasn't obvious.
What you did was probably clone it without making it unique. In S3OC, you must tick Renumber/Rename internally and set it up with a new name. As far as changing the names of the rabbitholes themselves (I think it only applies to catalog description), it would be in the STBLs which can be edited from S3OC.