I won't disagree with the 2-4d/liberty combo as there definitely seems to be some synergy with that.

As far as 2-4d in general, w/out liberty, i'll stand by what i've said.  We stopped using it in our burndown maybe 15 years ago as it doesn't kill.  It will twist, turn morphydite things but it'll still grow and put out seed.  Works just fine as a helper in the fall though and we'll use it then.  

I went back and reread what you posted and I did misread that so sorry there.  As far as post residuals, I think if you can had something in the post that brings residual and helps with contacts then that's probably good bang for your buck.   The success of the post residuals are probably heavily driven by weather.