About to embark on my first parti-gyle next weekend. BW / basic Pale. For a number of reasons, I plan on letting the 6.5 gallons of first runnings sit while I boil the small beer first. (I’ll wrap a towel or something around it to minimize heat loss). However, I would like to FWH the big beer with a few ounces. Should I do this immediately on draining and let them sit the whole time, or wait the 1+ hour until right before I throw it back on the burner?