I thought that was a totally different program, not a fork? If it's a fork, I guess that simplifies figuring out which alternative to switch to the first time Spectacle gives me any trouble at all.
It says “based on” in the README, which could just mean “inspired by”, but it’s also in the license so I thought that it was an actual fork. Looking at the actual history would reveal the answer, but idk, works basically the same.