Desiring a "solution" is indicative of there being a "problem." It has not been demonstrated to my satisfaction that there is a massive problem that required re-thinking of what FM sats are all about.
Lots of users and limited resources is always ugly... whether it be traffic, water, groceries, black-friday sales, or working a new grid on a FM bird.
Rare grids or Field Day on a FM-bird may not be a "problem", but certainly does not hold us in the best light. I thought the purpose of satellite on Field Day was to encourage new users to the mode... would you introduce someone to ham radio by letting them listen to a rare dx pile-up?
An aside: is the use of QRZ? on the rare-grid side frowned upon? or would it make things worse? I think a lot of the errant calling is folks trying to separate from capture effect, or guessing when the rare one is listening. I hear this a lot on the ISS voice passes as well, where you can't hear the uplink of others.
Bill W1PA