How to switch from AMD GPU free to non-free/proprietary driver and back?

Hello,
developer of a SW want me to try to switch from open source to proprietary AMD GPU driver.
I do not know what is the best most safe/simple way of doing that and be able to return back.

$ inxi -G
Graphics: Device-1: Advanced Micro Devices [AMD/ATI] Renoir driver: amdgpu v: kernel
Display: x11 server: X.Org 1.20.10 driver: loaded: amdgpu,ati unloaded: modesetting resolution: 1920x1080~60Hz
OpenGL: renderer: AMD RENOIR (DRM 3.40.0 5.10.23-1-MANJARO LLVM 11.1.0) v: 4.6 Mesa 20.3.4

$ mhwd -l

0000:0a:00.0 (0300:1002:1636) Display controller ATI Technologies Inc:


              NAME               VERSION          FREEDRIVER           TYPE

       video-linux            2018.05.04                true            PCI
 video-modesetting            2020.01.13                true            PCI
        video-vesa            2017.03.12                true            PCI

I have found “sudo mhwd -i pci video-nvidia” that should “install the proprietary nvidia graphics card driver”

Manjaro has some GUI for listing GPU drivers( Manjaro Settings Manager / Hardware ), and checkboxes that suggest possibility to install/disable/enable, but in my case the checkboxes are not working. found here and this Configure Graphics Cards - Manjaro

Similar:

#1 AMD Ryzen 5 Mobile GPU proprietary driver for Linux
#2 Installing AMDGPU PRO by Archwiki - #4 by realmain

The AMD proprietary drivers are only available via AUR.

Please read this and follow the instructions on what you need to install from AUR.

https://wiki.archlinux.org/index.php/AMDGPU_PRO

Most people do not need to use the AMD proprietary drivers at all.

How do I enable AUR repository and not destroy my system? I want AMDGPU PRO for OpenCL for mining.
Is there any other driver which support OpenCL for mining on my AMD GPU?

You dont need it for that. You can just add it to the open AMDGPU driver with opencl-amd.
AUR is covered in the wiki.

https://wiki.manjaro.org/index.php/Arch_User_Repository