Hi and welcome to the forum!
I’m personally not aware of another plug-in that comes close to exactly what you’d like, so in case you are going ahead and create it yourself, as a start: it sounds like you’d want a docker. Did you see this section on dockers of the Krita Scripting School? If you do go that route, I can recommend installing this plugin: Python Plugin Developer Tools
Sorry that I can’t be of much more help, just got started with Krita and its API myself 
Good luck!