If I'm understanding your numbers, you're adjusting your Freestyle LIte to compensate for the difference between your meter and the vet's meter. If you take a look at the 2 charta in the
tight regulation protocol I'm linking, you'll notice there are different cut offs for when a cat earns a dose reduction. On a human glucometer, in a newly diagnosed cat, the cut off is below 50. On an AlphaTrack or meter calibrated for feline blood, the cut off is 80. With many meters, there is not a consistent difference between the numbers throughout the range so it's best to not to try to correct the numbers by a fixed amount. Rather, use the below 50 on your Freestyle as your point for when Beeba earns a reduction.
It takes 5 - 7 days for a cat that's not been on Lantus to build a shed. For a dose change, it can take 1 - 2 cycles for the shed to catch up to the dose change.
Beeba is in good numbers from what you're reporting. We recommend that at the bare minimum, get pre-shot tests and one test per cycle to insure that your cat doesn't drop into low numbers and experience a hypoglycemic incident. Testing every other day is putting Beeba at significant risk. Let me put this in a different context. If this were a child, would you test his or her blood glucose level every other day? I suspect that your pediatrician would encourage you to test your child before
every meal and probably at bedtime, if not more often. I am concerned that Beeba is dropping lower than you are seeing.
Generally, we suggest to people who cannot test frequently, that they drop their cat's dose. It's bets to err on the side of safety than to have to deal with a hypoglycemic episode.