Matte vs sealed finish on decorative panels - where do you land?

I've been through this exact fight with a set of walnut panels I cut for behind my TV. I went bare for about six months beacuse I loved how dead flat the shadows looked, then the dog brushed past them once and left a scuff I could never fully get out. That pushed me to try a matte water-based poly on the rest of the batch.

Here's the thing I learned. Sheen under angled light has alot to do with how many coats you put on. My first attempt was three coats and it looked plasticky in the afternoon sun. When I sanded back and did a single light coat, knocked down with a fine scuff pad, the relief still read as raw wood but it wiped clean with a damp cloth. On painted work like yours I'd guess one thin coat of a matte poly would behave the same way. The other option I never tried but keep meaning to is a hardwax oil, the stuff they use on floors. It soaks in instead of sitting on top, so there's no film to catch light, and it can be spot-repaired. Downside is you have to reapply now and then, which on a feature wall might be fine.

Given they're getting dusted constantly, I'd lean sealed but thin. One coat, matte, applied with a foam pad rather than sprayed.

I'd push back a little on reaching for a clear coat right away. I cut a set of relief panels in maple a couple years back for a restaurant entry, and I sealed half of them out of the same fear you have. Two years on, the bare ones still look better. The sealed ones picked up that angled sheen and honestly read as plasticky from across the room, wich is the last thing you want on somethig that's all about shadow play. What worked for me was a hardwax oil instead. Osmo on the oak pieces, and it barely changed the look at all. Dead matte, but it puts a thin protective layer in the wood or MDF surface that lets you wipe it down with a damp cloth. A scuff buffs out with a white pad and a little reapplication of oil. It's not bulletproof like a poly, but for a wall that only gets dusted it's plenty.

If you don't want any film at all, cut a couple of test offcuts, leave one raw, wipe it with a dry cloth fifty times and scuff it with a coin. That told me more in ten minutes than any forum thread ever has. Then decide based on how rough you think your client actually is on things.

Before you commit to either, cut a couple of scrap coupons off the same batch and test the finishes under the actual wall lighting, not the shop lights. On my last relief job I made 12 little test pieces and the winner in the shop was a diffrent finish than the one that looked right under the client's south-facing window. Angled afternoon sun will tell you more about sheen than anything else. Also worth wiping a test coupon with a damp cloth a few times to see how the paint itself holds up bare.

One thing that might tip you either way, since it's paint and not bare wood, you can always touch up scuffs later with a tiny brush and the leftover paint. I did that on some textured cabinet doors and you honestly can't spot the repair unless you're looking for it. So going bare isn't as scary as it'd be with stained stuff, where a scuff means refinishing the whole panel.

Total beginner question from me, but does putting that clear stuff on change the color of the paint at all? I painted a headboard last year and tried some kind of protective coat on it and it made the whole thing look slightly darker and warmer, which drove me nuts. Also wondering how you even clean the bare ones without ruining the flat look, like would a barely damp cloth be ok or does that leave water marks on paint?