You are right - this is getting annoying. Since the gym in our club has reopened, I've been able to work out again and it feels like my strokes are coming together. I'm hitting the ball harder and with more spin than before, and so again I had **another** string job of S7T break on me. Only this time, it was at a grommet on the **bottom** which has never happened to me before, and it was a sweetspot hit off a really fast incoming groundstroke where I also put a hard swing at it.
Closeups with my phone camera of the break:
And both ends of the break. There's no obvious twist in the string so I think I got it around that bottom grommet properly. The mains were strung at 49 pounds.
Not exactly sure what to do at this point. I still have a significant amount of S7T left, about a reel and a half, but I'm also too lazy to restring every couple of outings if it's going to continue to break. If anything, I'm going to be increasing my racquet head speed by about another 10% over the next couple of months. And I think the last two breaks have come from different reels.