While you may not have direct design wall experience with that particular product, your use with your son is definitely close enough IMHO to know whether it might work or not for a design wall.

To me, one of the joys of a design wall is to NOT have to use pins ... so the headliner may work with pins, but would not be as easy or enjoyable to work with. And we all like easy, when it comes to quilting!

I'm currently using a flannel backed tablecloth from the cheapie $ store. I have to use pins for anything with seams.
I'm planning on getting the insulation board from the lumber yard and like the idea of using a flannel sheet to cover it. Although I may stick with my original plan of using fleece which I've found works better than my current tablecloth Will experiment with one of the sheets from my bed. Lol!

You don't have to wash it, but if you need to and it does fall apart - it is cheap. I just run a lint roller over mine to clear threads and dust bits. I find that pieces tend to stick without pins to the felt easier than the flannel. I use the flannel for a large board on my back wall and have a smaller felt board that I can move around and keep pieces in order.

I use two cheap flannel back tableclothes. Have worked well for 4 years. Getting full of threads so may need to change but only costs a few bucks!

Those of you who have never needed to wash the fabric on a design wall must not have cats! :p

When I had Warm n Natural batting on my wall years ago, I did have problems with blocks falling off it. I think it may be because my dh made the design wall flat against the wall. I have since thought that covering styrofoam from the hardware store would work better since I could prop that against the wall and the batting would then not be straight up-and-down; the slant would help keep the blocks in place. Ideally I would "box" the styrofoam with lightweight wooden strips which would extend beyond the styrofoam to create legs. This would lift the styrofoam off the floor so I wouldn't have to bend down as much (and also so the cats would not be brushing against it all the time!). I like the idea of having a moveable wall too.

I have a piece of batting I use for my design wall. Works great.

Felt immediately begins to form little balls and snags as soon as you wash it. Also if you have cats or dogs it won't last long. Only useful for cut and paste in my house.

How does felt feel the impact of pets faster than flannel or fleece, Madame kelly? I admit we have a cat who considers the design wall to be her own private climbing adventure space, but I rather think that felt is holding up to the weight of a cat's body suspended by claws into the fabric better than flannel would. She is most likely to attack the design wall if there are any flying geese blocks -- our theory is that in her primitive little brain the vaguely bird like shape triggers a hunting impulse.

This particular cat has a love/hate relationship with all things quilting related. I've witnessed her pulling every pin out of pin cushion with her teeth, laying them in a neat pile, and then taking off with the pin cushion as her latest prey. She also is prone to lick best press residue off of any surface that may have had some overspray. She's definitely weird and a bit of a menace.

I must tell you that I have a twenty pound cat that loves to "kill" anything made of polyester, and a huge dog that thinks he has to love on any fabric he can get his paws on, and until recently had a big hairy dog that shed poofs of hair everywhere. Flannel, they only want to sleep on, so if it is on the wall they ignore it. (Also I dislike anything sold as fabric that cannot be washed as needed.) Even silk can be cleaned and worn or used again. Sorry if I put my opinion badly. No offense intended.

I used felt, tacked it to a wooden dowel so I can roll it out of the way when not in use. After a year it was not longer sticky. Apparently it needs some static electricity to hold the cloth. I took it down wet it slightly in the sink, threw it in the dryer on delicate good as new.