Dog ear from upper blepharoplasty - should I get it surgically fixed or try more injections?

Bumps on the end of the blepharoplasty incision can happen. If the injections (likely Kenalog/5FU) do not improve it then excision is best. Typically, if the bump has not improved after 3 months then I offer excision.

If multiple injections of, most likely, local corticosteroid, did not help, excision of the lesion should be done. Good luck.

Sorry you have this. Intralesional steroid injections typically do not work for this kind of issue. So, no surprise at the lack of success after two attempts. One simply approach is to simply "sculpt" the protrusion off flush with the surrounding skin and let the site heal. A second approach is flatten it flush with surrounding skin using electrodessication and then let it heal. Both approaches are performed using only local anesthesia and neither approach requires any stitches. You would be wise to consult with an experienced, board certified cosmetic dermatologist. Best of luck.