Sorry, me again...Still WAY too much time on my hands...
Never had a stack pack on BRe, but conventional sail cover.
I had a soft sail tube/cover made up that went over top of whole thing, once disconnected from mast.
I used to have a couple of trips a year away maybe 6/7 weeks ? (work_holiday_work) boat on mooring as a bit of a faff to pull out and get in the field at home. Often meant loosing a couple of potential trips out on the days b4/after travelling.
I'd fit the sail/boom tubular cover, take the whole unit off the mast, including boom, kicker etc and stow it in cabin via a cut away lower washboard, together with mizzen on mast. If v early/late in season, sometimes I'd take the furled jib off too if fretting about gales.
Whole lot under an all-over cockpit cover. Clean, dry, no UV. No risk of rodents!
That way only needed a pal to keep an eye to waterline (flooding) and chafe on mooring bridle.
Otherwise BRe with mooring cover, furled jib, and sails on has a LOT of windage.
Once saw a fully rigged (with all sails hoisted and furled) partially flooded D lugger closeby blown over on to her beam ends and sunk in heavy wind over tide conditions.
...worked for me!