I used to do the same, sitting in front of the bedchair on the ground when I was carp fishing.
I did buy a chair more for pike and roach fishing with fold down back legs and ended up with that across the bedchair at times. That lasted a few years until the material started to split, so I got the Sonik, which I think lasted a maximum of 3 years until the weld came apart.
I do now prefer sitting on a chair with the back and hip problems I have, and if I sort the bivvy out tidily it can stay up permanently during a session, put to the feet end of the bed at night.
The chair stays in the boot of car, in layers, barrow at the bottom, chair on that, with chesties, wellies and Kelly Kettle and some cardboard and twigs in a bag fitted in the gaps and unhooking mat on top.