Here is my new fix for Memory leak issue, that's works on every GPU! (no need for GPU with 20GB or higher VRAM and basicly is smillar to fix via Nvidia CP AF/clamp settings)
https://www.nexusmods.com/witcher3/mods/8083
+ some others Tips, Check it out ! =)

Here is new version Memory Leak Fix 1.1:
https://www.nexusmods.com/witcher3/mods/8083

Thanks much for your great MOD work! does this mod help for non RT cards with VRAM usage maybe?

Np. If you have GPU with 4GB VRAM or lower and playing on DX11 or DX12 (better DX11 for higher performance) then probably yes, someone wrote comments that this helps him on DX11.