He will definitely love the space to climb and jump in his new home.
The perches are safe, but as said, they will get smelly very quickly. You can make tube like fleece covers for the perches that can be washed frequently to extend the life of the wood if your gliders like them in the cage, but eventually they will need to be tossed.
I found the perches (unused) worked out to be the perfect way to block my gliders from going under the pocket door to the bathroom and into the wall (after Sassy showed me that this could be done). I slid two of the perches under the door through the metal bracket on the floor. As a bonus, I could slide them out when I closed the bathroom door for glider play time and they also blocked the space under the door that Sassy had used for her escape after moving the towel I had been putting there.
The small cage may be handy to have for short term use like for car travel, or even to hang your glider's pouch in on the days you might take the new cage outside for a good scrub down and hose rinsing. I have a small hamster cage I use on cleaning day. My gliders just sleep undisturbed until their clean cage is dry and all set up for them.