Hi,
sadly my OSMC installation died a few days ago with the SD-card. No, I had no backup. 
So I reinstalled OSMC on a new SD-card and setted it up completely. Learning again how to handle my remote, learning it to lirc, doing keymaps settings, etc.
Then I updated to latest OSMC and it looks like the setup overwrites remote.xml with a packaged version - is this wanted?
Nevertheless, as I have already other RPIs booting with NFSroot I also wanted to have this for OSMC raspberry, prefereably complete SD-card-less. So I do not need to worry any more on backups or whatever, as my NFS-server is backed up. 
I did the setup and I guess I found some maybe common pitfalls like:
- does not boot up at all as in OSMC-boot-directory the start.elf is missing (only start_x.elf is there)
- does not boot up completely as it waits for /dev/mmcblk0p1
- needs an additional “rw” in cmdline.txt to do not mount the nfsroot in read-only mode
My current setup:
- SD-card image of mmcblk0p2 shrinked to 3GB size and mounted on NFS-server into a directory
- tftp-root has a softlink for the rpi-serial to the boot/ in the image above - I copied the complete content of mmcblk0p1 to boot-folder in the mmcblk0p2 image. the TFTP-root directory needs to include the osmc-filestructure, otherwise it is not able to follow the symlink to boot/
- in boot/ a softlink for start.elf to start_x.elf
- cmline.txt looks like this: root=/dev/nfs rootfstype=nfs ip=dhcp nfsroot=192.168.0.1:/home/raspi-images/osmc,v3 rw rootwait osmcdev=rbp2
So, as I read in some other posts, OSMC should be installed (instead of imaged) on NFS-roots - but what about the boot folder there? Kernel is loaded over tftp from the boot-folder, how does it look like on an update for a NFS-root-installed OSMC?
Are there any issues I will encounter on an update, either kernel or osmc itself, with my current configuration / structure?
Is there a howto around for migrating an existing installation to SD-less one?
Thank you!
Best regards
Alois