I would say be careful what you wish for. The biggest issue would be lounge access on low cost intra-Europe routes. The easy solution would be to remove it from all IAG carriers up to and including band 3. Introduce same rule that BA has about no additional status luggage on HBO fares and you have probably just saved the IAG Group a lot of money and now all its airlines can afford to be OW members.
That addresses the OP’s concerns about TP/Avios earning, but I sense it might not be everyone’s optimum solution!