If you want to set certain weapon to cause potion effect when attacking. You as a Modpack maker have to select BOTH Attacker and Victim potion effects, or it will just not work.

In default options you left example of Ink sak => blindness, and glowstone => Glowing scripts.
they both not work. Untill you add attacker potion effect aswell.

Confirmed, looking into it

This should now be fixed in the latest release (071)