Hmm. Not exactly what I had in mind. What a monstrosity this thing is.

They claim you can type up to 85 wpm. I might be able to type faster.

I assume that if you’re right-handed, then you’ll use your mouse on your right hand. So you would need the left-handed version of this keyboard.

Anyone here ever use it before? Any feedback?

It's intended for people who only have one working hand / arm.

The company also make keyboards for people with no working hands.

https://www.maltron.com/store/p24/Maltron_Head%2FMouth_Stick...

I'm right-handed and use my left hand for mousing. I originally swapped so I wasn't having to move my hand over the number pad to get to and from the keyboard. I don't use a keyboard with a number pad any more, but I've stuck with it. It's quick to learn.

Not exactly the same but this might solve your problem. I am adding a trackball to my dactyl manuform mini so I don’t need to switch between the keyboard and the mouse on my right hand.

It might be faster to train your off hand to mouse than to train it to do all the typing.