I think the important thing is not the brand of the adhesive... it is the amount you use on the surface you will apply it to that is important. This comes with time and experience...
I've been heat stretching polystyrene sprue for an entirely different purpose this morning.
I don't think these are perfect for applying CA because making them is a bit of a faff and when the ends get covered in dried glue they are done for. However, for getting tiny tiny amounts of CA into places out of reach of the usual tools, they might be useful. High viscosity CA formed a tiny bead on the end in the quick test I just did, I don't think the runny stuff will work with these applicators.
You are right... but it seems more logical to me to use the one with medium viscosity by pouring some of it on wax paper and using a thin toothpick to apply enough glue to the area to be applied.