Does this exist? Concept -- neutral ergonomics with a couch option.

Tenting is definitely helpful, but I've noticed that even with typical tenting options there is still often some ulnar deviation, pronation, or extension of the wrist. And none seem to address that humans have opposable thumbs!

Does anything exist that is fully neutral (i.e. imagine holding a sandwich or a clarinet)? See concept below --

https://imgur.com/a/kT7DhQh

Also is there anything out there with a beanbag on the bottom? Would be really handy for working and PC gaming on the couch.

It would be great if there are options that can be 3D printed for DIY. Haven't been able to find any fully free designs on GitHub made only from AliExpress parts, that'd be ideal.