Custom icons for folders inside drives, should be supported on both Windows and Linux?

I know how to change the icon of a file/folder on Linux (using Dolphin in my case). I know also how to change the icon of a file/folder on Windows 11, both directly in the parameters and using a desktop.ini file. I'm more interested in this second option because I want to cusomize icons on an external sotrage unit (so the drive contains the icons it needs to display, and so I need to have the system look at the relative path --on Windows at least, with these stories about varying drive letters). But when I'm done creating (and hiding) all the desktop.ini files and my folders look all pretty in Windows, and I go back to Linux... The icons are the default icons. I expected that much, so I changed the icons the Dolphin way, in the naive hope that it wouldn't beak my "Windows setup". But it did! On Windows the nice icons don't show anymore, the folders are back to default, *even though the desktop.ini are still there and unmodified!!*! This is really anoying. The exact details: there a a few folders on my drive, and the first one (Backups) looks like this: * Backups * desktop.ini * .hidden * .directory \- desktop.ini: [.ShellClassInfo] IconResource=..\.icons\ICO\Backups.ico,0 \- .hidden: System Volume Information desktop.ini \- and .directoy: [Desktop Entry] Icon=/run/media/myusername/Appendix/.icons/ICO/Backups.ico (Appendix is the label of my pendrive). So if anyone has tried this before, all help is welcome. I think I'm close but something's eluding me. I guess on the Windows side.