I may be wrong but I think you can contact makers on AliBaba (wholesale wing of AliBaba group which owns the retail wing AliExpress) I think and have whatever you want custom made such as blades , rubbers, balls etc even in small quantities.
I myself am looking for some manufacturers who can make small quantities of blades & rubbers.
I want to flood the market with rubbers not on LARC but with improved modifications
I don't think you understand the OP questions. There are only a few "high end" rubber manufactures in the world and most of the brand gets oem rubbers from these manufactures.
China does have many small brands, that does make they own rubbers, and blades.
I would advise to be very careful on Alibaba, as any tom dick and harry can be listed, and next thing you know, your with an agent, of an agent of an agent of a small manufacture that outsources to another manufacture.
I get spam with some of these agents, some may be real manufactures, but the MOQ for custom range is normally in the 10k unit.
I have no intention of what you have, so I never investigated further. But good luck trying to find "improved modification" for the so call low end rubber manufactures, what ever you do, try to patent it, and maybe you can become very wealthy if your modification is succesful