Covering all the bases as I've also asked this over on FT. I think from what I've read that I cannot use my BA miles to MFU into F from an I fare, but would like to confirm with the experts. Scenario: I'm flying MIA-CDG via LHR in late June, with the MIA-LHR leg on AA 56 (777). I've purchased an I fare. I know I could use AA miles + copay to MFU into F, but I'm curious to see if I could use my BA miles. Since it's not full fare, I think the answer is no. Appreciate your confirmation or clarification.