@Full and unquoted argument

Hello. I've got strange results.

Current directory is "Z:\PortableApps"
It is working fine in TCC/LE

[Z:\PortableApps]echo %@full[c:\Program Files]
It looks wrong. Even if quoting would be required.

TCC 17.00.69 x64 Windows 7 [Version 6.1.7601]

Merry Xmas :)
While v16 also documents the need for quotes, it behaves a little better.
v:\> ver & echo %@full[c:\Program Files]

TCC  16.03.55  Windows 7 [Version 6.1.7601]
C:\Program Files