I'm using RAM Disk v4.2, and tried to redirect Edge browser cache folder to my RAM disk with Cache Relocator v1.5.
It works, but now Edge creates two duplicate cache folders with the same files and contents: one in my RAM disk cache folder, and the other one in the default HDD folder "C:\Users\Mario\AppData\Local\Microsoft\Edge\User Data\Default\Cache".
I use the Windows 10 21H1 version and Edge version 91.0.864.48 x64.
MS Edge is not creating two copies of the cache. What's happening is the Cache Relocator creates a symbolic link in the hard disk folder you mentioned. However when MS Edge writes into it, it actually goes to the RAM disk. The folder in your user profile is merely a link to the RAM disk location.