Aw - he is so cute. I sense you and Bernard are quite close already! I'm sure he liked the fleece as well and didn't just see it as a tunnel.
I wouldn't normally put a fleece hammock in a cage (even though Pip doesn't chew). It was because the Plaza is so tall and it was intended to be right up against the top bars (which it more or less is) to partly make it darker and cosier underneath, and partly so he couldn't get onto the roof bars. I never expected he would get up there! It was a bit worrying when I found he could get up there, but he can't fall out of it as it fits the full width of the cage and no gaps. One side is over his shelf just below - not a big drop. The other side is over his egg box hammock (which is how he gets up there - uses the egg box hammock as a step up).
The only other time I've used it was for the same reason but with a very old hamster with no levels (ie to add some darkness and just in case they happened to climb the bars, so they couldn't monkey bar across the top).
So it can be risky - unless you know your hamster doesn't chew.