Max had a beautiful morning cycle on 3/19 with all greens and blues, but then you did a dose decrease (probably based on the 51 reading) and he kinda went to hell after that, what with constant bounces and lack of testing data, etc.
Here's what I think, and what I would do if this was my Pumbaa. And trust me, I am NO expert at this. So, since this is free advice, use at your own risk!

I would drop him down to 1.75U (or lower...maybe back to 1.0U?), and wait 72 hours for the shed to deplete before taking lots of new readings and trying to figure out his numbers. Then, depending on his numbers after his shed has depleted, I would decide on dose increases or decreases. But do take time to let him settle in to the new lower dose. And start testing more regularly. Pumbaa needs a long time to settle into a dose. When I see him flatten out, and clear all bounces, I know it's time for a dose increase (or decrease). ECID: Every cat is different! Your Max and my Pumbaa are not poster cats for the tight regulation protocol, that is for sure!
Don't forget, if you miss a dose, or think you gave a fur shot, you start over analyzing the BG numbers at the start of the next cycle.
Do get the magnetic dry erase board to record the numbers, it will simplify your life! And do start bribing Max during testing time. Pumbaa now purrs on my lap during testing time, even though he seldom gets his sardine treats anymore. This is only because I made testing time a ritual/positive experience (with bribes), from the very beginning.
Oh, you don't want to run a curve during a bounce or new-dose-wonkiness. That is difficult when our cats react differently all the time, that is for sure! Once I thought I had Pumbaa figured out (he had his lowest numbers 4 cycles after a dose increase) he proved me wrong and threw me a huge wrench by dropping down into the greens in the first cycle after a dose increase! They sure keep us on our toes, don't they?
Suze