Currently, FocusGTD does not yet support the new "dropped actions" feature which was released by Omni last week.
However, Omnifocus will notice that you are using a sync client that has not advertised the availability of this feature and therefore will show you a warning in case you would try to force a database migration to enable this feature.
I will be analysing and trying to add support for this in the coming days but will probably take a week or two to get this production ready.