If one isn’t afraid to tinker a little more while building keyboards one could work in a nice!nano or similar replacement for pro micros/elite-Cs, I had a fine time building a kyria (a 40% split) with it too:
Can you replace any existing usb c ports with this? I have a planck that I would really like to make wireless but a quick search around google doesn't show anyone building one with it.
https://nicekeyboards.com/nice-nano/
If you’re into low profile switches (that’s a big if!) there are projects the corneish zen https://lowprokb.ca/products/corne-ish-zen