This is a good reaction to the insulin and good drop on the .5.
I think I would be very careful increasing to .75 based on these numbers. Remember, he appears to have a late nadir--around +8, so he probably will drop some more. You have to be real careful basing your dose on the preshot. The nadir is as important as the preshot and you must consider the two together.
An increase to .75 would be a 50 percent increase on your .5 dose---that is a big increase based on your numbers this morning.
If you do think you need to increase, I might would try to just do a Fat .5---a "little" more!
Eventually, once he settles down and you get on a "normal" shooting schedule you can concerntrate more on getting him in better numbers. With so little data, and the events on one unit and the "crashes" at the vet---I would be leary of .75.
Okay, I just felt a need to say that! Others might disagree, and I do agree that eventually you might see a need to increase to .75--but, I am not sure I would increase to that on the next cycle. I would take smaller increases and see where it led me.
I am no dosing expert----
Are you going to test him around +8? If so, post your test results--some others will be along and I will check back before 10:30.
You are doing Great....keep checking for ketones!
Just my thoughts!