What do you mean? You want to follow a list but not create a personal copy of the whole list?
Is that so that the list can continue to be updated on the "curator" side and your list will stay up to date?
Discussion
If that's the case, you can sort of already do this (not yet in Listr) by just referencing lists in other lists (via `a` tags).
This will take a good bit of work to visualize properly in the UI, which is why I haven't yet tackled it.