[tzs]

You are correct. Even spacing does not matter.

There are many initial configurations that achieve the maximum time before the last ant falls off the stick, and that includes configurations where they are evenly spaced and configurations where all but one ant is randomly spaced (achieving maximum time requires that at least one ant be in a particular initial state--I'm being vague to avoid spoilers).

(This is all assuming mathematical ants...point sized and can change direction instantly)