[swagasaurus-rex]

I've struggled to find split keyboards that work for laying down. Most split keyboards have a cord that runs between the split even if they're advertised as bluetooth.

[mgsloan2]

Some have swappable cables! Ergodoxes typically use TRRS audio cables. Keyboardio uses ethernet between the two halves.

There are also some fully wireless split keyboards like the southpaw centromere. I found the thumb keys to be too inward / too few for my taste.