Well “spray paint” is overselling what they have there. it’s a clear matte finish, so you can spray it on your existing gold stuff and it just gives it a matte surface. It might still be too glossy.
Then there’s this:
https://www.amazon.com/Specialty-Frosted-Glass-Aerosol-Alkyd/dp/B081TL8B75/
Which is like a frosted glass spray. Might give you more of what you’re looking for? Hard to say without trying it, and I’ve only ever used the clear stuff to seal paper on my mandalas, like this one:
I made the layers, glued them up, then sprayed with the clear sealant to protect the paper. It didn’t change the look of it at all, but then paper is already matte.