Hmmm... I love forgotten threads.. :)
Sim link in my Windows 10 works perfect.
This works for OBS-Studio 27.1.3 (64-bit).
Open an administrative command prompt and type in as follows (example):
mklink /J "C:\Program Files\VSTPlugins" "X:\Location\where\ever\you\have\your\VST-Folder"
Don't leave out the quotes, they are necessary.
Gud luck....