This is NOT the solution ..
All laid back sitting postures have 1 thing in common. it is trying to relieve you of having to use core, back, and hip muscles to remain upright.
This coupled with the quantity of time we'd spend IN such a chair, leads to atrophy.
The Atrophy leads to general bad posture, be it hip rotation, or sloped backs.
The poor alignment leads to unnatural bone wear, giving you pain in odd places.
Finally it all culminates in a young guy mopping about like the hunchback of notre dame.
---- Except in the real world, you don't get the girl.
Standing desk is the right way to go..
Even then, you can't stand all day..
For the few hours that your legs will give out, take ANY chair, sit at the very edge, feet on the ground, BACK STRAIGHT..
Rotate your hip forward as much as possible.. Use your MUSCLES to keep your lower and upper back in a position similar to standing..
---- If you can't do that, it's time to go lay down and sleep..