Out of curiosity, have you tried something like -v D:/Drone/Flights/20190807:/datasets -v Z:/Drone/Flights/20190807/Ortho:/datasets/images ? That way you don’t need a code change and your scripts can do the right thing. I tested something similar and it worked:
~ ❯❯❯ mkdir -p foo/bar bar/baz && docker run -v $(pwd)/foo:/foo -v $(pwd)/bar/baz:/foo/baz busybox ls -al /foo
total 4
drwxr-xr-x 4 root root 128 Aug 13 22:41 .
drwxr-xr-x 1 root root 4096 Aug 13 22:42 ..
drwxr-xr-x 2 root root 64 Aug 13 22:40 bar
drwxr-xr-x 2 root root 64 Aug 13 22:40 baz