I just installed a 6 liter stainless thumper on my 15.5 keg boiler with a 2" slanted reflux column. I was running a 3 liter thumper but it kept getting overrun as I reached about 178* so I went to the larger one. I've made 2 wort runs with it and both times it was almost empty at the end of my runs at 185*. My thump is running about 6 degrees behind my head vapor temp so I had to run the column up to 190* to get the thump at a tail temp of 84. I'm priming with backins from several earlier sweet feed mash runs that are fairly high proof. My product proof is pretty typical of what I was getting before but my volume is up about 25%. Is this a good thing or am I pushing my cook to far? I run LP up until I smell my heads then switch over to a 2500 watt lower and 1500 watt upper coil heat system controlled by a dual SRC unit. I haven't noticed any off flavor.