Folks,
Simple facts... as the scrubber gets used its *less* efficient. So using it deep/working hard on it when its partly used is a moving line of risk.
In plain english; A smaller scrubber (either by design or by use) doesnt scrub as well. This is particularly true at depth.
Some folks might get away with nice relaxed diving on it, but if the brown stuff hits the spinny thing, you run the risk of a meeting with Mr CO2. Using other peoples "experience" doesnt necessarily equate directly to your use.
If you truly want to push your scrubber for 5 hours, or take a dinky scrubber to 100m, I salute you and praise your bravery. However, I won't be following you..... I have an affinity for red wine, perky breasted women and thai food, none of which tend to be available after a CO2 hit at depth
You can always argue that the limits/CO2 generation used in the developement of duration testing are conservative. You are indeed correct, but you have to ask yourself how much you personally are prepared to push those limits.
Safe/fun diving... one and all!