I wouldn't do it
I'm sure there is room in the inmast cavity for furling - The gentlemen that delivered my B321 a year ago split my mainsail right in half - leach right back to luff - about 10 feet -- when it was repaired , in stead of replacing the panel, the sailmaker applied a 6 inch wide patch which effectively doubled the sailcloth thickness when it was furled - I've had no problems - other than I hate to look at it.But I wouldn't use patches - it seems most Beneteaus have the spreaders set well aft of the mast - but there is no real friction between the mast and mainsail - they just rest there.