I think UDF was meant to be this, though I don't think it supports everything you'd want. Does NTFS have licensing issues though?
For example ReFS removed the MFT which caused various problems.
The MFT was annoying because if you create 1 mil files, and the delete them, the MFT will not be shrunk back.
Have you ever benchmarked it against NTFS? With the same exact set of FS filter drivers running on both? How much does the performance differ?