UltraFastCopy does not provide closing handles under Windows.
Because this is a very dangerous method.

If you close a handle used to write to a file, the software using the handle is unaware of this.
It continues to use it as if it were open.
The most dangerous thing is that the handle number is recycled and contains another file.
The first code, unaware that the handle has been closed, continues to write “normally” as if it were in its file, but ends up writing to another file…..

See Microsoft’s Raymond Chen’s explanations on this subject:
– https://learn.microsoft.com/en-us/previous-versions/technet-magazine/dd547078(v=msdn.10)?redirectedfrom=MSDN