Damn... it feels like a big setup. So what mouse companies are genuinely doing R&D? Zowie? Mionix?
It isnt exactly like it was mentioned, IC and SROM(the Sensor Firmware, which can be tweaked depending on the capabilities of the brand) are provided by Pixart, actual Device Firmware has to be written by someone else(either by the brand or the factory), same goes for PCB design, ID, etc.
Which in the case of Zowie is done by Kingsis, and everything they do is based on the Deathadder, including 10 year old MCU´s.
Mionix is basically LaView, just slightly modified designs(by LaView ofc.).
Logitech and A4Tech are doing stuff completely in House, including Production.
Razer, Roccat and SS do design and Firmware inhouse and Production is outsourced, mostly to Dexin and LaView.
CM Storm buys Designs from Dexin and lets them do modifications to the ID and EE, except for their ultra low end stuff.
Finalmouse is buying OEM Mice from Motospeed.
Cougar, EVGA, Corsair and ASUS have contracted the designstudio Cre8 for most of their mice, Production and other stuff is again mostly done by Dexin and LaView.
Ducky is using some taiwanese factory for everything, apparently the same as Epic Gear, which also explains why the tooling is crap.
Func/Fnatic, i dont even care, and i dont even want to know given the overall quality of their products.
Qpad is using LaView for everything.
But tl;dr is that only Logitech, Razer, Roccat and SS are actually doing something, with varying success ofc.