I'm no expert, but you could try to add some plants (even fake ones) in the middle, where there is alot of unused space. The plants on the sides are good, but does not add much to climbable areas since it's along the wall of the tank.
And by middle I don't mean in the middle on the back wall, I mean volume-wise. Where there is alot of empty space.

This might not affect the direct health of your frog, but the frog will have a slightly better place to live