The parent is storing files on the "Windows" part of the filesystem and accessing them from WSL, while my post (and https://blogs.msdn.microsoft.com/commandline/2016/11/17/do-n... which it indirectly links to) refers to storing files on the "Linux" part of the filesystem and accessing them from Windows (apparently some files must be in the Linux part, like certain configuration files etc.)

Incidentally, the response from a MSFT employee about why this isn't a problem with Samba is "Because this isn’t a supported mechanism for accessing files via a networked file access protocol; it’s what happens when a hacker modifies files stored in a hidden system folder.", which is pretty much a non-answer and almost a "you're doing it wrong" accusation in an attempt to hide from the fact that they seriously screwed this up.

What is the problems? I have been doing this for one year without issues.

From https://blogs.msdn.microsoft.com/commandline/2016/11/17/do-n...

Therefore, be sure to follow these two rules in order to avoid losing files, and/or corrupting your data:

DO store files in your Windows filesystem that you want to create/modify using Windows tools AND Linux tools

DO NOT create / modify Linux files from Windows apps, tools, scripts or consoles

Remember: There's a reason we gave the %localappdata%\lxss\ folder 'hidden' & 'system' attributes

That's talking about manipulating files in the LXSS filesystem from Windows tools. There's no problem with doing everything on your Windows mounts, assuming you don't mind everything getting +x.