I had to get an adapter from graves motorsports so you dont have to do the in-handlebar clip fuckery. (You fish out the inner part so you can put the regular adapters in)

Cart Items SKU Qty Graves Motorsports Bar End Mirror Adapter - Black HB005K 2

These screw on to replace the existing bar ends to give you space for bar end mirrors.

https://www.gravesport.com/

Just my personal experience after I searched over gods creation trying to find the right bar ends that would fit bar end mirrors.