does a unibody tented ergo keyboard exist?

There's the btrfly which is a dactyl manuform variant. Not sure it it's what you're looking for. https://github.com/SolidHal/btrfly-keyboard

I believe I've seen one before on the site that shall not be named, but I can't remember which one off the top of my head. IIRC it was a handwired board, or was it something that used a corne pcb on either side? Crap I can't even remember now. I'll look into it and give you a reply if I can mange to find it again

The Kinesis Advantage2 (and earlier Kinesis Advantage/Contoured models) have 20 degree tenting built-in. Also the usual ergo features (column stagger, thumb keys) and key wells.

closest I know are still row staggered

• full size – KBDfans Mountain Ergo and gok’s Type K (still in IC)
• 40% – Libra Mini (the board with a joystick) and Sonatina’s Cisne

beyond that, are things like custom cases for existing boards – tented Sofle case

Shameless plug for the Mantis keyboard I'm working on. It raises the central index finger and thumb keys to create about a 15° tent and an approximation of a key well at the same time. The inspiration comes from ThumbsUp!.

I saw this the other day. It's column staggered with a fixed 10° tenting.