Deck stringer attachment

Had this inspection on new construction today. Walked around the back and saw this long set of stairs leading up to a screened porch about 9-10’ above grade. I have a couple of questions.

1st, the set of stairs felt wobbly in the center. Is there a reference I can point to showing the need for support in the middle of the stairs other than “feels wobbly”?

And 2nd, the stringers are bearing on the rim board only about 2". They have added a useless support backer below to give some support but I feel this is inadequate. Again, I’m looking for something to reference for the report.

Thanks in advance.

Thanks Joseph, thats what I needed.