At first like the others, wtf, then, creatine is used to increase ATP so why not, plants use it too. I also found another study from 2021 about phosphocreatine - didn't read it. If some plant additives contain citrates because it's involved in the Krebs cycle, then the thinking doesn't seem absurd to me.
I'd tend to agree with Benzels. When the ec is way too low, like with RO, the plant will drink more water than necessary and it can be detrimental. But i have no idea if the plant stores more water because of creatine like we do. And i also do flush sometimes with RO... Why not trying?