Before we talk about underclocking, let us first talk about spike.
You captured 7 screenshots of his ping where he doesn't appear to be spiking, but I wouldn't take them into consideration because Ace was indeed spiking but not consistently. The screenshots are not conclusive because you missed capturing the times when he actually spiked, as you can see from one of the few instances in the replay:
https://gfycat.com/OilyFalseFoxterrier
Apart from the spiking, I don't see any common signs of UC like weird turns or jumps in his movement. It is a
no from me.