I would hold steady for now. This 2.25 unit dose got him into the 50's and that's a good nadir. We determine whether to change a dose based primarily on how low it can take the blood sugar. Bounces can take up to six cycles to resolve, so just keep on with the dose for now and we'll see where he goes when the bounce breaks.
As for testing, you can probably take a break until PMPS time.