If you're putting something like a DK-4 (circular eyecup) on it then be careful. If something else more streamlined then it may not be the problem I had. (not sure what exactly you want to mount on it)
Edit: if you are putting something like a DK-17 on it then it should not be a big problem although any easy-on/easy-off accessory is easy off when you least want it. I think the DK-17 is very similar to the original FM-2 eyecup/eyepiece)?