After observing Charlie for a while, I have noticed that he is not comfortable on flat surfaces. I think his right foot needs to constantly grab something, and when he is on a flat surface he puts the right foot on the left foot and grabs it.
I bought some soft materials, mainly faux leather with and without padding, and used the one without padding to cover a platform I made for his cage. It wasn't a great success because it's flat, but I added a strip of weird material on top of it and now he uses it to reach his water bowl and one of the food dishes

This is that weird material:

No idea how it's called, but when I saw it I thought I could make ladders with it. Charlie can walk on it pretty well, but he doesn't trust it very much yet.
The cage I chose for him is the old hospital cage; it opens on top and one of the sides opens completely so I thought I could use it as base for his playpen, but it's too small so I will go back to the original idea and build him one ad hoc, low and large.
He needs perches all around because he can't hop from one to another so I need more space to make something decent.
One of the materials I bought is padded, and I have been using it to cover the perches with it, so that they are soft and comfy.
As you can see from the photos below, I haven't found a very good way to fix the padding to the wood stick, so for now I am using ties and they make the perch look like a string of sausages
This is the material:

And these are the perches



He is quite comfy on them and he sleeps on the one in the cage, but they are horrendous. Please please give me some good ideas on how to fix it to the wood perches without those ties!
He hates that plastic platform, can't blame him... so that has to go.
I will make more platforms covered with the faux leather.