How do I stop MCreator from regenerating the main file?

I literally just need to know how. The issue is: To avoid MCreator from deleting custom files in net, I created the package "bai". However, Forge loads net before bai, and one potion effect inside net requires an attribute made inside a file in bai. I could register it in the main file, however MCreator always regenerates it and erases the line of code that does it, and if I set to "readonly" MCreator makes a huge drama and doesn't even start the game. So sick of this