Bob ....
The conversion of hank-on sails to 'continuous support tape' luffs has been going on now for about 30 years with success. True, a sail on a roller furler will simply become a baggy pillowcase at the first % of furling; however, .... If correctly 'converted' a sail on a roller furler CAN be reefed down **by 30% sail area reduction** .... and still have 'good shape' above that 30% reduction by adding foam padding at the luff, using altered luff hollow shapes, etc, etc. etc. . There are other 'tricks' to increase this % but for the average, 30% is about a good correct number for maximum furling-reefing with most modern sail materials. 150% X .7 can be successfully reefed down to 105%120% X .7 = 85%100 x.7 = 70% ..... and if correctly coverted/designed will have relatively GOOD shape down to this 30% SA reduction limit. I prefer Harken furlers because they can withstand higher halyard loads .... needed to correctly SHAPE a furlable or hank on sail made of woven dacron/polyester. It may have changed but CDI furlers dont operate with traditional halyards ... and therefore the shape adjustment on a jib/genoa is impossible. For changing jibs ... consider to purchase a furler system with a two groove foil. Then (just like is done with the 'twin-groove' foil Tuff-Luff system used on racing boats) to change: raise the other sail in the additional groove, tack, then *peel* down the sail that needs to be removed. .... and you wont lose 3 inches or 3 seconds of sailing time if the raise is done on the windward side of 2 sails, and the 'drop'/peel is done on the windward side of both sails. If you're not racing in precise high quality fleets .... I will wager highly that once you start using a furler-reefing system you will hardly ever ever need to do an inside / outside 'peel' for a jib/genoa to replace whats already on a furler. Betcha you just simply JUST furl the installed foam-luffed 150, etc. hope this helps.