Sorry to hear you're still having problems. If you haven't done so yet, I'd "forget to mention" having an outside 'smith work on the gun when speaking with Springfield. They could use that to void your warranty. Probably a small chance of that happening but it never hurts to be cautious, SAs aren't exactly cheap and I wouldn't want to be stuck with any further repair costs.
Good luck with your 1911, please keep us informed as the situation progresses. I'm normally a Colt fan but with their cost (and current QC issues) I might try "just one more" Springfield in the near future.