Aerox 5 Wired

I went on this journey last year and gave up. I didn't like the aerox 5 enough to keep it. Felt cheap, the third button was almost too easy to press, but I never got around to finding out if I could get used to it because the mouse felt so bad in hand compared to all the other quality mice I own and have tried.

As someone else said, the Aerox 5 by Steelseries is probably your best bet. I'm not fully sure what you mean by commissioning a company to make a single mouse for you or what you expect out of that. Besides the custom shell and PCBs you'll also need custom software to bind that key to a keyboard button since Windows only recognizes mouse1 to mouse5. IF they'd even do that for a one-of unit, you'd probably pay thousands of doubloons for that and it'll probably be 3d-printed and won't be near the build quality of an OP1 let alone the software being bug free on the first attempt. If you want it to be an actual injection molded shell you could actually get a new car for the amount of money the tooling would cost and factory slot that it will take up.

I feel that. The aerox 5 had ping wheel issues but I love love love steelseries. They've never let me down. Thats like one of their largest flaws. And that specific mice if what i need for fps so I was trying out other things. I just got my v4. I want to try the pro x2 superstrike when it comes out but thats not until jan-march of next year. Not to mention its a heavier (65g) mouse. Guess we will see if thats to benefit or not. 

Yes, and it's one of the only remotely "modern" mice to have more than 2 side buttons if not counting Logitech's G502 series and similar mice. Glorious isn't worth being in any discussion since their shit isn't even worth getting for free. If wanting modern "lightweight" though, yea that don't exist LMAO.

I have big hands (measurement unknown), I used a razer viper mini for quite a while. Having moved from the Deathadder elite, in a palm grip, the mouse felt tiny in my hand. Eventually, I became comfortable with a pseudo-palm grip, where my fingers and thumb were in the same position as they would have been on the earlier mouse, but the heel of my palm on my mouse mat, gliding along it's surface. I've since switched to the Steelseries Aerox 5 (I think?), which feels slightly bigger, slightly lighter. I'll also take this opportunity to say the following. Mice with cutouts, in a honeycomb or other pattern, look like they'd be super uncomfortable compared to a uniform 'intact' mouse. This actually isn't the case. Similarly to a bed of nails, pressure is distributed evenly across the case of the mouse in such a way that you can't really feel the individual cutouts.