The Lagrange keyboard (repo) is an open source, handwired keyboard designed for ergonomics. It isn't new, it was introduced around New Year's (featured in KDB Issue 10), but papavas tried to improved the design further with the newest iteration.
The design now features an optional "bridge" accessory, which attempts to address the last remaining grievance the author had with it, namely that due to its split nature, each side tended to drift out of place over time.
Besides requiring frequent readjustment, this also gives your hands a "moving target", in the sense that the key placement it needs to adjust to, is always different. It's also made significantly worse (with respect to a typical split keyboard, like the Ergodox say) by the high tenting angle.
The bridge is a linkage (made from printable parts and easily sourced threaded rods) that can be adjusted to hold the two sides at a given separation distance and "toe angle". You adjust it once (well hopefully, or at least rarely if you have to experiment with different setups) and the sides stay at the same relative position, as if the keyboard wasn't split. Secondarily, it also serves to guide the cable along the bridge and keep it out of the way.