Anybody made a synthetic sleeping bag?

[WoodBow]

I can't find much quality intel online for synthetic ones. All the backpacking guys are making down bags. I made an apex quilt a couple of years ago that has served me well, but I am wanting to do a bit of a quilt/bag hybrid build. Basically it is a tapered quilt except for that it is fully enclosed. So kind of like a mummy bag without the hood, and with a system to attach it to the pad so I don't slide off of it and theoretically so I can toss and turn independent of the bag, like I do in the quilt.

The apex only comes in 60" wide which is a hair narrow to do a bag out of a continuous piece. So I designed it to be two halves instead. Will have a side zip. Will have a shock cord cinch around the top. Fully enclosed foot box.

Probably going to make a detachable hood that can be moved to the top for belly sleeping if desired.

I have a lot of layup ideas floating around in my head, just looking for some insight from someone who has already walked this road.