Ised to repair RB lenses (and Blads, plus a few others) for a living, and honestly, if the lens is in good condition (in other words has had a proper service in the last few years where worn out bits like the mainspring were replaced) then it doesn't matter if it's stored cocked or uncocked.

As for "long term" storage - I'd call leaving a lens sitting in a cupboard for 6 months or more long term...