Dont think its a problem at all for the sails;infact its probably better for them than continual rigging derigging and leaving sail on mast untensioned definitely puts creases in them....
Few years ago I bought a sail that had been rigged and untouched for 2 and a half years. (Was from a shop and it had been used as advert on ceiling)
When derigged I carefully compared sail with a "brand new " one.. There was no difference in luff lengths or shape.. Sail sailed perfect and is still going strong. (A Tush T Bird 7 metre) I dont think modern sails stretch much; they burst when over stressed...Stresses involved with rigging are small compared with abuse they get on water.. (Especially wave sails)
However the mast had a slight curve and I`ve witnessed quite a few masts from hire centres with a similar pre-bend in them... In theory the carbon masts shouldnt go this way but they do !!!! (Not all though ????)