Tricky situation, I have codeshare booking made with old rules that I need to move. Y flex so no issues BUT after quickly chatting with AY prices for similar codeshares have increased but cheaper fares are proposed on AY metal.
Now, as we all remember, important thing in Ay loyalty is not to fly with AY so I'm in a pickle. Try to find non-ay flights and pay more, with certain uncertainty what earnings will come out, or take AY flights and accept very odd TP's.
I guess I need to go in middle ground, at least it allows then upgrading and maybe still like 75% of original tier points If only there would be AY promotion, I would just cancel the trip completely and rebook with refunded amount.

I can not even search options on the MMB due to non-AY tickets so I guess best method is look at booking engine for similar Yflex tickets and propose routing option directly to CS.