There is no .cfg file within the config folder, so no option to config. When going into the actual game, there is no option to config when looking in "Mods".

Similar issue here. I want to whitelist some non-stackable items, but cannot find how to. There is a config file in worldname\config\toolbelt-common.toml ... but no whitelist/blacklist options or examples.

The whitelist/blacklist are in the server config.
You'll find them in the save folder, inside serverconfigs. toolbelt-server.toml
If you are making a modpack, you can copy the file over to defaultconfigs/ at the root (next to configs/), so that they will apply to new saves.

Thanks gigaherz ... i found config file, edited, and had whitelist changes working via the location you gave. :)