No, I do not think the AA flights open until 330 days if I recall correctly. My guess is you would need to buy an AA ticket to like DFW and then book the BA flight using points at the 355 day point. I suppose another option would be to fly to Chicago and take BA from there. I do not recall if BA flyies from Chicago.

AA releasing seats so late does make it a challenge. I still use AA from time to time as I used it a lot in my working life and have been a platinum flyer for decades. One of the things I did back in the late 1970's was buy a lifetime Admirals club membership for something like 350 or 400 so have gotten my monies worth from that purchase.

I have read good thinks about Finnair so that seems like a good idea. Playing the mileage game is a challenge. Good luck.