Hello. My set up is 50/34 and 11/36 and I have a 10 speed SRAM Force road shifters. I know I need a compatible long cage rear derailleur but there is a medium cage SRAM GX 2.1 10 speed at a local store on sale 50% off. This GX 2.1 medium has the spec of 32 cog and 35 max. Will adding a derailleur extender work with my set up? I know I can just get a long cage and be done with but if it works and save a few bucks, why not. Thanks.