I got the same situation as you before. What I did is working on refile PERM and file EB1-b (OR) almost at the same time. I filed OR first while getting all my PERM internal posting, id number ready. Luckily I got my OR approved before refiling PERM. If you think your case is strong enough to give a try for OR, it is worth of doing it. I think PERM is also a faster track than waiting endlessly for the backup center's processing date. You never know what happens.