Larry,
While I, personally, agree with your above statement as far as MY use of steel in my BSS goes, notice that it does not agree with Browning's statement. I have shot 3" steel loads, up to and including no. 3s, in my 30" BSS for many years with no ill effects. Important to note that I opened the left barrel to the same constriction as the right, which is .018".
From Browning's statement above:
3. DO NO USE ANY STEEL SHOT LOADS:
The Belgian-made A-5, Superposed, Leige, and other Belgian Over/Under models, Double Automatic, American-made A-5 and all other models not listed in category 1 or 2.
The BSS is not listed in Cat. 1 or 2, so falls under this caveat in Cat. 3.
SRH