Did you McLube the mast again and again? It really makes a difference to do it LOTS of times because the lubricant gets transferred to the inside of the mast sleeve. Also lube the cams a bunch of times. I did that with an old nitro that I was using on a fat old ck75 neil pryde mast and it really made a difference. McLube aint cheap but it's worth it considering the depreciation of the sail and the mast. Don't be penny wise here.
Still, it was a lot of work not to completely crease the sail each time rigging. I'd consider selling the gtx before the monofilm gets ruined and it's resale value goes down even more...