I think there is no solution yet, it will probably solve itself sooner or later.
You can add a filter of ,url!~"europe-north-1.tardigrade.io:7777|us2.storj.io:7777"
to the fields which are not undefined i.e audit would look like this: avg(storj_sat_audit{type=~"score|auditScore",instance=~"$node.*",url!~"europe-north-1.tardigrade.io:7777|us2.storj.io:7777"}) by(url) * 100