yeah her holding this over Oliver for so long was kind of dumb. It seemed like a rather shoddy way to keep them from being married.
As to a timejump for the show, well they could but since the show is linked to Flash and the Legends and Supergirl, a timejump for one may mean a timejump for them all unless they don't plan any more crossovers.
A major downside to a time-jump is that it means we get more flashback stuff. I hope that after this season we are done with 5 year flashbacks because they have just about caught up with season 1.