[Zope] downgrading from 2.1.x from 2.2.0 to use NTuser authentication

I would really like to use the jc/ntuserfolder products but see that they haven't been brought up to speed with the new 2.2.x security model. Will downgrading to 2.1.x render my site inaccessible? What will I have to change security wise so I can use these pages from the old version? Alternatively, I might take a stab at bring the jc/ntuserfolder up to date with the new security model - any insight from those in the know appreciated(am I underestimating that task?). Thanks, -- Erik Myllymaki