It seems as if the uBlue images ship the required OpenRazer kmod by default. Therefore, I would suggest you to take a look at those. You still need to follow some additional steps though 😅. Which might not be very intuitive… Thus, I propose the following: if you’ll rebase to uBlue, you might as well rebase to Bazzite. After the rebase has been completed, the (post-)installation software should already give you the option (it’s just a simple toggle) to install OpenRazer. The toggle is clearly visible in this frame.
If you perceive Bazzite as too opinionated for your taste, then perhaps you might opt to the following instead: