You can mount any ordinary computer that goes on the handlebars on the stem if you are willing to do a little work. I keep the material left over from cutting fork steerer tubes. Cut a one inch piece off. Split this in half with hack saw lengthwise. Now drill four holes for zip ties to mount to your stem. Now drill however many holes you need for zip ties to mount the computer to this piece of carbon. Use a bit of double sided tape on the bottom of the carbon to fix the position. Don’t breathe any of the carbon dust.
One little trick I discovered when mounting my Sigma 800. It had a lot of wire so I ran the excess under the right hand bar tape (one big in and out running toward the brake hood and then back to the computer). Looks much cleaner than wrapping the wire around the bar.
Ciclosport’s HAC4, etc have a rotatable clamp so you can put it on either way. I use the HAC4’s baby brother, but I don’t know if all of the computers use the same mounting system.
Cross two zip-ties w/rubber spacer for grip. I have mine looking seemless setup on my vision tech intergrated bars. Nice because it sits lower than if you had it on a base mount.
I made my own “movable” clamp. Used extra carbon extensions from aerobars (or fork steerer, mtb hbar) about 1". Got a velcro strap around it and duct tape in place. Now I can mount any computer on the stem, aerobar or the “much criticized” spacer. In my pics it was the sky mount that I used. Velcro makes it easy to attach and remove to different bikes. I just adjust the orientation of the computer or skymount to angle properly. Cost, about 1$.