20 lumens isn't anything close to being a daylight visible taillight. 60 is barely.

20 lumens is technically daylight "visible" in that people can see that it's on if they look right at it, but that's not the purpose of a daylight taillight on a bike; if the driver is looking at the bicycle already then the taillight isn't needed. A daylight light must attract the attention of a driver who is not looking at the bicycle.