https://nascompares.com/answer/how-to-recover-synology-raid-including-shr-with-ext4-or-btrfs-file-system-using-a-pc-should-also-work-with-qnap-asustor/
How to recover Synology RAID including SHR with EXT4 or BTRFS file system using a PC - should also work with Qnap & Asustor