The repeat function has in fact gained this capability in v0.12, as you can now set a gap between the repeated elements, and whether to justify them (i.e. whether the gap can be increased to completely fill the available width). If you combine this with a right-align, and a constant width of all page numbers (which is still a bit annoying to achieve), this should make the dot alignment possible.
The API and behavior should be the exact same as in the outex code piece you linked.