I had used a utility called Hetman Partition Recovery(Windows) to recover data from a VMFS data store. IDK if this would work in your case but could be worth trying.
If you manually configure the 'child' to connect to its 'parent' then think it could be OK. The issue gets to be when you allow 'auto mesh' they might not connect how you want. Within UI of Unifi controller you can manually set uplink.