Originally Posted by transpac
It is of course possible to fly on UA and reap
some status benefits (uprades) while crediting those flights to another *A FF program, and thereby acieving status in another prorgam for the following year. (I'll admit it can be challenging to do this.

And you give up MM accrual, 2x RDM, COS EQM, exit row/E+, meal choice, etc.) This might be the primary benefit?
However, unless you expect to fly regularly on both airlines then there really is no sense in doing this, as far as I can determine?
why not fly till 2P and then wait for the double EQM to come out during oct-dec...fly once so in the end you'll spend less