If plan A provides early retirement and is merged into plan B, which does not provide early retirement, is there anything that would prohibit separating the benefits earned under A and B for annuity starting dates?

Am I correct in thinking we must preserve the timing features of A's benefits even if they are more liberal than those allowed by B? It seems strange to allow commencement of benefits from a portion of an accrued benefit.

I think you have it right. You must protect the payment options based upon benefits accrued.

I agree wih Andy. When he states "protect the payment options", it would be prudent to consider the option factors in A versus those in B.