Even if you are using your FF acct on this segment and your BP shows no status, you can definitely flash any other OW status card and they will treat well during boarding and at the gate. I am not sure if this is part of the rules, but I have found CX to be fairly good at recognizing OW elites. If the elite is one of their own flying on a codeshare for business reasons or whatever, most agents seem to be very sympathetic.