Modder/dev build?

Will it be possible somehow to have a separate gamebuild that I can use when testing my mods out? I’m thinking I that I want to keep my regular game and characters somewhat separate from the modtesting, in case of corruption and such.

keeping your characters separate is easy

all your characters are currently stored on your computer
so just copy the folder somewhere and make a backup

as for the game you can always jsut install and uninstall the mod
you aren’t actually changing the game itself
http://grimdawn.com/guide/settings/Grim%20Dawn%20Modding%20Guide.pdf

Ye i know that you can move the saves around and install and uninstall mods back and fourth. That is kind of what I’m trying to avoid, i probably want to switch between playing normally and building my mod fast and without hassle. The process becomes even more daunting when I’m using mods myself when playing.

I’m currently running the Steam version and that’s why I’m asking. I can kind of think of a way to do it with the GoG version, but I don’t really want to buy the game a second time just for this.

Using GOG would not help with the characters as it uses the same save location as the Steam version.
Well, unless you are using Steam’s cloud save feature, then the save location would be different.