SJS-
I happen to usually agree with you but in the interest of intellectual honesty I must point out that I think the Ben Ish Chai you quoted will not help here, and that is because he is clear* that the halacha of ervah with regard to krias shma is entirely subjective to societal norms. It might actually be in this very same halacha. Therefore in all honesty he might simply be referring to the norm in his day and age, which cannot be used to prove what the halacha is here, today.
*I don’t have the exact source offhand but I read it once and can get it tomorrow if you’d like.