I recall Resolve from headphones.com making a post about the differences in frequency response between the different pads applied to the old Focal Clear, but can’t say if the measurements would return the same with the Clear MG.

Leather pads to my knowledge would be elevating certain treble and bass frequencies, so it likely won’t sound similar to the stock pads they currently have.

Third party pads that aren’t designed from the ground up for your specific headphone are a minefield of random fuckups and poor decisions. They almost always break the tuning in one way or another. If you’re looking to change the sound, EQ is a much better solution.

If you Google search Reddit about the topic there have been a number of Clear pad swapping threads. Most people tend to go with stock or Dekoni but ZMF makes Focal pads as well, there just isn’t as much info about the ZMF pads.

Resolve has a write-up about the Dekoni pads and DMS has a short on his YouTube channel testing all 5 (including Stellia custom pads).

I use the Dekoni Velour on Clear OG’s and they sound pretty close to stock but I personally like the stock better, just they attract grime easier so I prefer the Velour earpads overall.