I had been considering upgrading, my current 4 bay Synology is physically full and running out of storage space. Moving that to a larger Synology box and adding drives would be easiest, basically plug and play.
But now instead I'll probably just switch to a more traditional NAS instead. Run TrueNAS, or maybe give HexOS a look. If I'm going to have to convert from my current proprietary Synology filesystem anyway I might as well rebuild from scratch. As it is I've shifted all the services off the Synology and Docker to a dedicated Proxmox box.