Yes that was the unacceptable attitude I complained about, a BA top tier frequently flier who buys a J ticket LHR-SEA-LAX-LHR, with 2 BA segments & lounge access, expects not to be turned away and fobbed off with excuses like you’re flying AA today.
But that's exactly what the capacity constraint rule is there for: to protect the BA lounge space for those who are actually flying BA. Do you think that buying a J ticket for some BA flights means that you are special enough that an exception should be made for you even when you're not flying BA? Did you perhaps actually mean to post in
this thread?