Also one thing that's really interesting.
I pitched into the Porter at 21 degrees and immediately put it into a fridge set at 18 degrees (with the probe against the side of the fermenter and covered with insulation).
I pitched into the ESB at 21 degrees and put it in my second fridge and turned it on (this was at night time). When I went to work the next day I was backing out of the garage and went HOLY SHIT, my fridge was showing 9 degrees! WTF OH NOZ I had left the fridgemate setting on that fridge at 2 degrees and so the wort had dropped overnight down way below the desired temperature. I turned the fridge mate off and opened the door of the fridge to let the beer warm up while I was at work. Came home and it was 18 degrees so just turned the fridge on as per normal and set it at 18 degrees. I didn't swirl the fermenter or anything and sort of just crossed my fingers. I still got 70% so I guess this didn't shock the yeast too much.
However I'm wondering cause this is a mix of yeasts if the unintentional cold temperature allowed the US05 to flourish but not the windsor and maybe that's why I got better attenuation in that one? Totally weird either way. Maybe windsor was the dominant yeast in the porter with a constant 18 degrees and the US05 never had a chance to finish lower.
I don't know how yeast mixing works, just speculating.