I do some. Are the results better than before the frost? Not especially, but if the conditions were poor for control earlier in the fall then it might be better than then. There are some factors that deter me from doing a lot of it 1) ester or psuedo esters have the best control and cost a lot 2) leaves on lawns make it a challenge 3) always windy in later fall.
That being said late fall control is better than early spring control.
I just put down some broadleaf control about 2 weeks ago. We had received about 4 to 5 frosts before that. What I have really noticed is that the frost mostly takes out the crabgrass, goosegrass, and quackgrass. Nothing really else. Now that is my opinion and what I have witnessed.
Heck just today when I was mowing a lawn I saw a dandelion
A hard frost will kill off annual grasses and summer annual broadleaf weeds.
Perennial weeds will only slow down thier metabolism. So if you spray during or
shortly after the frost the weeds maybe slower to die, as the will translocate the herbicide much more slowly. But they will speed back up to normal as soon as the soils warm back up. So go ahead and spray the dandelions, clover, ground ivy, etc. after the frost but I wouldn't bother with spurge, knotweed, purslane or other summer annuals. Just a waste of herbicide.