water level sensor accuracy/sensitivity?

[Kungpaoshizi]

So, I have a 48x24x10 tank now. Nice big footprint matched by the amount of evap! :/
And I'm wondering, what's the smallest amount of vertical distance the water level sensor will detect? I mean, can I keep the water level within 2-4mm? I know the pump would be running quite a bit, but short of the micro ato or the titanium one, I think this might be acceptable?
I was planning on the 4 channel sensor, then having an upper #, lower #, too high safety #, and then the ATO bucket #..

[rimai]

I think it should work, but you may see it turning on/off very often.