I'm going to be switching from my current carrier, where I have Oneworld Emerald status, to BA due to a move to London. Unfortunately, they don't match status in any way, so I'm going to need to log flights using my Exec Club number to get up to Gold status. In the interim, would the check in desks and lounges at Heathrow allow me to use my Emerald status using a card, even if it's not listed on the booking? Skipping the lines and using first class check in is not something I'd particularly embrace losing during the transition. Thanks in advance for any guidance or recent experiences.