I recommended a kernel mount because libsmb doesn’t offer the same speeds or performance. It will work – but if people get stuttering or buffering the first thing we recommend is an OS mount because it’s much better
For me it didn’t work at all which is why I’ve opened this thread.
If you want to stick to Kodi method than check out this thread
Alternatively change to fstab based mounting. If you don’t want to loose your library you can either use path substitution or export/import your library.
You could also enable NFS on your Synology and mount using that protocol instead. It works fine in my setup (also mounted via fstab). I can share my fstab config if you need any further help.