I'm sorry you didn't get a reply-- I'm not a Prozinc person so I don't like to give specific recommendations on shooting or dosage, but he sure looks close to an OTJ trial!
On Lantus, we do one dose below the 0.1U. You push the plunger in as far as it will go, insert the syringe into the vial, then release the plunger to let the vacuum suck up a tiny bit of insulin. Not sure if you do something similar on Prozinc. Another way to get tiny doses is to count drops. To calibrate doses, you draw up an easy-to measure dose, like 0.5U, then slowly let it out to get a count of drops in that dose. So if it's 15 drops (picked for easy divisibility, ahem), then 0.1U is 3 drops, you would get it by drawing the 0.5U and letting out 12, and then you would have two more stops along the way.
Whatever the next step is, he's looking great!