I think quite a few people, like me, are running Hass.io on a Pi but configuring ‘recorder’ to store its database on a Synology NAS. This improves performance and should be a lot kinder to the SD card!
But I had another (very modest) idea last night for connecting the two together: Synology’s new (and very nice) Active Backup app is a great way to backup the config directory on your Pi. Lots of backup options and once you’ve set it up you can just forget it…
I’m just connecting via the Samba share, but you could also set up rsync over ssh if preferred.