I am not an expert so do not know what is different but I found Raspbmc allowed me to access NFS shares by just choosing them. For OSMC when I installed on my RPi 2, I had to ssh into my Synology Diskstation to change the /cat/exports file - first following instructions from another post and then experimenting a bit as I do not know the set up well enough. I could see the shared folder but could not then select or see subfolders/files to add as a source
It would be good to not need to make these changes - the main one which I think made a difference seems to be taking insecure_locks out. This did not seem to affect or be needed by my raspbmc set up before. I got the instructions from a Youtube video on How to Setup NFS Shares with your Synology - YouTube. First part of the post in Synolgy gui was already set up and current DSM gui is slightly different but the second half on using Putty/ssh was the part I had to do.
Seems to all work now but still importing to library!
This would be ideal but we have absolutely no control over remote devices that are not running OSMC software I’m afraid.
We do our best to ensure compatibility. This includes patching the kernel to reduce SMB share security requiements, NFS version levels etc. At some level we can only do so much and external vendor changes are necessary
Yes, I had got NFS shares working with Kodi previously (for over a year I think) including a fresh install of RASPBMC on 24th Dec 2014 without needing to refer to the Kodi guide. Using same set up and new IP for new Pi it did not work without referring to the Kodi page you mentioned but for detailed instructions of using Vi, I used the Youtube link and a Vi page from Colorado State University. The Youtube page highlighted what I think was the main issue with the standard Synology permissions using GUI - the ‘insecure_locks’ part.
The reason for post was more to see if this could be avoided or made easier for non-skilled users like me through a feature, which Sam has also answered - unfortunately no-one can predict what manufacturers will change and what will be included in their GUI set up.