No, the plugin was created by me.
I know it's the AI era right now, but I rarely pay attention to what's selling on the RPG Maker plugin market, I only know long-time devs like Yanfly, Visustella, and Kage Desu,... All of these plugin contents originated from my own projects, as I needed them for my personal projects. Personally, I just focus on making plugins and mostly play games with my friends, so I would not waste money renting AI and leaving it there for nothing.
My editor style was inspired by and learned from SRD plugins from the MV era:
https://someran.dev/rpgmaker/plugins/mv/SRD_SuperToolsEngine.js/
You can also check my Steam profile. I play CS and Naraka quite a lot: