conf-sanity calls wait_osc_import_state on the client node (the node that runs the test script) to run lctl list_param and grep for params of the form osc.lustre-OST0000-osc-MDT0000.ost_server_uuid. These params are only present on the nodes that host MDTs. For review-dne this wastes about 20 minutes per session. This is why it prints the confusing:

can't get osc.lustre-OST0000-osc-MDT0000.ost_server_uuid by list_param in 40 secs
Go with osc.lustre-OST0000-osc-MDT0000.ost_server_uuid directly