I’m basically designing to be chewed constant by the CAG ( in a hope it leaves our doors and window seals alone, although I do know it won’t happen
I had hardwood furniture/trim in our house when I got my CAG. Also, made a ladder out of solid oak for him. As a baby, he couldn't chew either, and grew to ignore anything that looked like those woods. All the toys I gave him, were all dyed some non wood colour, and perhaps a combination of that, and learning early that he couldn't chew finished wood appearing things, set him for life to not want to even attempt.
I've been using construction lumber to make my bird toys for close to 30 years. Spruce/pine/fir tree wood; I take 2x4 lumber, and use my band saw to remove a few mm off each side to get rid of any contaminants (you can use a smaller hand held saw like a Milwaukee model 2420 mini sawzall if you don't have a bandsaw; the purchase price will easily be made up over the years by cost savings in bird toys!). Then cut into appropriate sized chunks / drill holes in them for hanging toys. I only use metal chain that's too small for the bird to get his toes caught in, or leather straps to hang the toys. I use 14 gauge steel wire to bend in order to attach the chains to things like eyescrews in the wood, as my CAG can't unbend steel wire. Just file off any sharp points from the wire you use.
Though I started with birch dowels, now many of my bird's perches are cement, as it's natural roughness helps control the growth of toenails and the bird can rub his beak on it too, to get the shape he wants or to just clean off his beak (you can make them from pouring some cement into food wrap tubes sealed on one end, and then stood on end, and then sticking an attachment bolt deep into the open end before it hardens; just add food coloring to the cement mix while mixing, if you want fancy colour perches). For smaller birds, cardboard tubes of different diameters can be had from hobby & craft shops, and the bolts, washers and wingnuts from any hardware store. Cement perches are easy to clean, last many years, and just brush off with a wire brush, then rinse and bake for about a half hour to kill any germs on it.
Edit: there are contoured cement perches available for sale, and my birds like them. But you can also make these, by squeezing the cardboard tube in various ways and holding it in that shape with a pair of vice grip pliers as the cement hardens. It doesn't have to be perfect, remember branches come in all sorts of shapes, too, in nature. This way, your bird has a variable shape perch to stand on, without switching perches.