If lounge access is your is one of your priorities get the AMEX Platinum and you get Priority Pass for free.

Being in Barcelona have debated for years wether to change to IB. Have been EXEC PLAT with AA for the last ten years. On the move now to most likely BA EXEC. GOLD on IB DO NOT BELIEVE GIVES YOU ANY MEANINGFULL BENEFITS.

My analysis for my own travel patterns seems to give me an advantage of attaining OW EMERALD with BA. I considered changing to AF KLM FB but EMERALD from OW is in my opinion the best and almost always able to redeem flights in premium cabins.

About what customer service and IB websites says GOOD LUCK, I could ant about their lack of clarity and misinformation only way is to take it up up the chain of command.