I'm also a big fan of working while reclined. I am less fancy, and probably less ergonomic about it. I will sit on a recliner couch, or in the warm season I also sit on a zero gravity chair[0] outside, on my deck, in the shade. In both instances I sit with a pillow behind my back... to make the seat less deep / keep me propped up a bit more I guess?

FWIW, I probably sit 2-4 hours reclined on couch or recliner chair, 2 hours standing, 2 hours in traditional chair.

0: https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...