Can you point me toward any documentation on the additional tags you want to support?  Searching for IO_REPARSE_TAG_IIS_CACHE mostly seems to yield header files that define it (and nothing at all on MSDN), and the non-Microsoft tags just yield a few results each.

(For comparison, the junction and symbolic link tags yield 10K+ results each.)

Junctions are created with each user's home directory so they exist on every Windows system, even if the user never explicitly creates them.  The additional tags seem like they're far less common and much less well-documented.