Not sure if this will help, but I just PC'ed my BoA travel rewards card to a cash rewards card through the chat option online and received the cash card yesterday, whole thing took about two weeks. First they check to see if you account has the option, if so they ask you to use up your rewards first as they do not "swap" over to the new card. NO credit report pull on this for me....NOT sure and I kind of doubt if they will do this for a co-branded card BUT use online chat when available or call and ask....pretty painless for me....good luck!!
PC between Cash Rewards and Travel Rewards is possible.
BoA will not let you PC to any partner cards (i.e., Alaska Airlines, Amtrak, etc.). Believe me, i wish they did. I've talked to members of management multiple times at BoA and asked to PC my Cash Rewards to Alaska Airlines, and they simply will not do it. They say it is not possible due to partner agreements and fees. There has been one person who has gotten around the system, but BoA is really pretty adamant about not doing this.
Best thing to do is apply directly for the airline card of theirs that you are interested in, and if they deny the card, ask to move your limit from your current card for them to open that card. Good luck ML. 
Bank of America does do product changes but they are limited to their core products excluding the Better Balance Rewards. None of the partner cards are allows to be PC'd to or from. The core products that support a PC are the Cash Rewards, Travel Rewards, and Secured cards.
I guess I must have gotten pretty lucky. I have a card that started off as a secured card, unsecured a while back and about 2 months ago I called in and got them to PC to a BBR. No change in credit limit (that would have required a HP which I declined). Doesn't hurt to ask I guess.
