"OK. Ran my cleaning (50:50 vinegar:water) run two days ago. Fixed all the water leaks on the cooling system. I bought a 1.75L of the cheapest vodka I could find and mixed it 50:50 with water. I have the PSII with induction kettle, ran it in reflex mode. I had it on a 1500W hot plate from Amazon. It heated up faster than I expected. I turned on the cooling water after about 20 min of being on the plate. The temp shot up shortly after and hit right about 170F. I started collecting a few min later. I collected about 50mL of the first part of the run, then about 4-200mL mason jars before the temp went up to about 180F and the flow slowed a lot. My questions are:

1. I could not tell a difference from the heads, middle, tails. Is that because I ran commercial vodka and it was already very pure? All the jars smelled and felt the same. And since I ran reflux would I not even really have heads?
2. How do I slow down the run? Does colder water and more water going through the column slow it down? I was using a smaller cooler with ice water, and it started off very cold, but as the run went on I had a hard time keeping the temp of the cooling water down. When I do a real run I'll use a bigger volume of water.
3. My second and third jars were about exactly 180 proof. The last had dropped to about 90 proof.

My temp was stable about 170F the whole run, I couldn't tell if adjusting the flow on the column was changing the collection rate or not, so half of the run it ran the valve half open, the second half it ran it full open. For a very brief time it was collecting around 158 or so, but it was so fast I almost missed it.

I feel like it ran too fast, but I don't really have anything to compare it to. I should have timed the flow, but it was like drip, drip, small stream, drip drip. Should my proof be higher if it ran slow enough? My column is packed with copper.

I want to run a few sugar and/or wine runs before I switch to pot mode and start running stuff for flavor.

Thank you for all of your help and suggestions.

I have a sugar wash going right now, should be done in about 3-4 more days."

A commercial vodka wont have much if anything for tails but it should show heads. You can tell the difference by smell and taste. Smells and tastes very medicinal. Hearts should have almost no smell and taste very smooth.
You can slow your run down by increasing cooling to your reflux condensor and/or turning down the heat to your boiler. I don't think you did too bad at 90 percent but you should be able to squeeze a couple extra points out with some tweaking.
The best way to determine flow rate is by monitoring the proof of the distillate collecting.

Sounds like you did pretty good for a cleaning run. I would definately get a bigger water tank for your condensors. Consistant water temps to your reflux condensor is needed for stability throughout your run.