I've been busy building a few Mantis v0.3.3 builds for friends and family. It took me way longer to build these than I had planned, and I still have a few more builds to go before I work on the next version of the design. But I'm getting better at this, and very happy with how these turned out. It's nice to try out different switches. On these boards I used Choc Sunset, Pro Red and Pink switches. They all work great with the sculpted key caps.
The two keyboards in the front use clear acrylic case plates and key caps made of two different resin materials to highlight the home keys. They are translucent enough for the backlight. The one in the back is made with birch plywood plates, painted with 3 coats of shellac to bring out the wood grain and lightly sanded for a matte finish. The key caps are grey nylon. The small holes in the skirts work great for letting the backlight shine through those opaque keys.
I used KB2040 controllers from Adafruit for all these builds and loving the extra space for building the firmware with Vial support. My old v0.3 prototype with a ProMicro also works with Vial, but I had to disable some features and lighting effects to squeeze it in.
Everything except the Y key you can get with a Perixx Periboard 535. It uses mechanical Choc switches.
The closest thing I've seen to moving keys to the other hand is keyboards with two B keys, so you can type it with either hand. I haven't seen that for the Y key.
You didn't specify whether you want row-stagger or column-stagger. Given that you don't want to change your typing habits, I'm guessing row-stagger is what you'll prefer. Transitioning to column-stagger would throw out a lot of your muscle memory and require some time to adjust, especially if you're used to non-standard fingering. Typing Y with the right hand would be a minor change in comparison.