Many growers are applying Cadre or Impose for broadleaf weed control, control of sedges, and suppression/control of grasses. Although we don't always observe it, Cadre/Impose can cause peanuts to grow more slowly for a period of time and you might see the "yellow flash" (chlorosis) in the canopy a few days after application. This is transient. I would apply Cadre/Impose 3 to 4 weeks after peanuts emerge and not 1 to 2 weeks after emergence. A good approach is Gramoxone plus Basagran (with a residual herbicide) 2 weeks after peanuts emerge followed by Cadre/Impose a few weeks later. If your PRE herbicides worked well, you might be able to skip the Gramoxone mixture.
In many fields with Palmer amaranth, Cadre/Impose will need to be mixed with Ultra Blazer or Cobra. The timing of the mixture needs to occur before Palmer amaranth gets beyond 3 to 4 inches.
Cadre/Impose has good activity on many of our annual grasses. Before you apply a clethodim product, make sure you get all you can out of Cadre/Impose on grasses.
Cadre/Impose are absorbed through the foliage and roots after a postemergence application. That's why we often have better control with these herbicides when we get good rains for a few weeks after application. Out contact herbicides and clethodim do not have appreciable root activity.