See #89 (comment) as current case where we have problems with not automatically detecting not-compacted keys. (Although I knew about this change and should have prepared the context, a test would of course be fine to catch it when we miss something.)
quick note: curl weywot5.hbz-nrw.de:9200/gnd/_mapping | jq -r 'paths | map(.|tostring)|join(".")' |grep http.*properties. |grep -vE '.properties(.id|.label)(.*)$' |grep -vE '.properties$'
where have to get the proper index name of course.