You'll want the HW SCT Pro esc for short course 550 motor application.
I have the V3.1 with a 4.5 540 motor and in TC, it already gets pretty warm.
Well, I went with the V2.1 120a instead. I got it all installed in my SCTE 2.0 with my Ballistic 4.5T 550. I did some test hits on the street and that yielded no issues. I went dead stop to WOT to full brake with no hiccup. Actual track testing will be later this week. I will report my findings as soon as I can.