4Game

As of version 2.4.3, MO2 now supports Valheim. Mod Organizer 2 is a popular mod manager initially created for Bethesda games, but now has basic support for many others. What makes it rather unique is the fact that it uses a virtual file system in order to install mods without ever touching the actual game files. From the mod page:

"The special fact about MO2 is that it uses a Virtual File System (VFS) instead of actually installing your mods into the folder of the game. MO2 uses it's VFS to trick the game and other programs into thinking that the mods are installed in the game folder while they are actually installed in their own separated folders. This VFS is called USVFS (User Space VFS), which is different from the VFS that MO1 used, since the old one did not support 64bit programs, but it works on a similar concept.
Which means that only programs started through MO2 will see the mods, while for the rest of the world the game will remain vanilla."

It should be noted that if you use MO2, you should mark it as an exception in any anti-virus software you use, as the way it redirects program file requests from the actual game folder to its virtual one is similar to how some forms of malware behave, and thus anti-virus software may flag it down.

Here is a link to MO2 for those interested. Don't worry that its the Skyrim SE nexus, this version works for all supported titles: https://www.nexusmods.com/skyrimspecialedition/mods/6194