[Zope] INSTANCE_HOME and products that patch Zope

[Mitchell L Model]

What do people do if they are using a multiple-instance Zope setup 
(INSTANCE_HOME, etc.) and want to use a product that patches Zope 
code, such as TransparentFolders?  Are there just not that many 
products that do that?  Do they just install the product in 
SOFTWARE_HOME?  In other words, the multiple-instance mechanism 
supports Products and Extensions in each instance, but not Zope 
patches.  Seems to me you'd want that so you could experiment with 
patches (including, perhaps, hotfixes) without interfering with the 
production Zopes running off the same SOFTWARE_HOME.
-- 

     --- Mitchell