Don,
That stuff is fine for sh*ts & giggles, but please realize that by you "testing" a few times will only tell you on that given day under those circumstances those were your results.
It doesn't translate to a "these are my limits" absolute. There are way too many variables that can dramatically change those results.
You need to account for this with a healthy safety margin to avoid the one time that the rules don't fit.
Hey, can I gather from your tests that if I watch TV while diving I can get 7 hours from my scrubber?
Dive Safe,
Richie