I use a tankless hot water heater with a commercial chip to fill my HLT with close to mash temp water, and my boil kettle with close to strike temp water. BCS PID to get them to and hold temp. It’s almost always at temp waiting for dough in while I’m still grinding grain, and I don’t have to...
Once, my recipe called for 1.17 of one type of grain and 1.9 of another and down the list. I just got 2 lbs of everything... accidentally put it all in the same bag. Threw the balance of the beer all off. It was OK... just not what I intended to make.