I ran the formula on the top 500 SV OU ladder's glickos. It seems that showdown tends to overestimate values by 6-7%.
Couldn't find the real formula, but it should be noted that the correlation between them isn't entirely positive.*
For instance, when you rank by GXE, vosotros > ustedes is 21st with the PS! formula and 23rd with X-Act's, while Wolfey 2023 VGC, no doubt the youtuber's account, goes from 21st to 22nd.
If this is real and I didn't just mess up the math, it has some important implications: for instance, say you wanted a GXE treshold of what is 76.77% in X-Act's formula. This would include Marnie Christmas but exclude abr fan 1, JeremyBaffourDoku, SuspectOUCouncil, and hanwha life.
...However, there's no treshold that does that in PS's formula, because it considers Marnie to have a lower GXE than the others.
I doubt this ever changed a suspect result but I thought I'd let you know
*idk if that's the right term but you get the vibe