I'd love to use these rune arms, but they're up against so many rune arms that have more flexibility built into them. Like I mentioned before, the electric ones need something added to the attack itself - like a stun because the limited range makes it less then niche. There's no reason to fire it with less then full charge since the range is to short. And given that negative for a ML 25 it needs something extra. A stun like electric loop would make it a little better and useful.

Also an orange slot would allow people to seriously consider these rune arms since that would add an augment slot that is really useful on a rune arm. Most Arti's use 2 rune arms, force and something else. You can use iron beads for Toven's Hammer, Epic Rock Boots for acid based (only up to 90 spell power tho) but outside shadowmail the only way you can boost impulse would be in a red augment slot. And it's even worse for cold. Again, shadowmail only and frozen tunic.

By adding an orange slot you add alternative ways of boosting spell power for a diverse amount of rune arms and repeater combinations. Otherwise you force Arti players that have a hard time as it is to compete in end game DPS to slot all red augments with secondary spell power use instead of slightly better DPS.