It is down to decision making. If the FISO has cleared you across the hold and there is something coming, then by all means wait for the landing aircraft to land before lining up. In your situation I'd just wait until the landing aircraft has landed then line up and report lining up. I might tell them something like "after the landing aircraft wilco".
I think the idea of a FISO is silly. I think we should either have ATC or Unicom (with possibly a person in the "tower" giving us weather reports...or not).