Could just add custom increases to cooldown similar to things we ALREADY have in the game.
Eg consecration increases your melee cooldown by 40 %
However bungie is incredibly stupid and have zero foresight when it comes to making any type of change so they will most likely screw up
So the way I would attack Aspect balance would be:
1. Buff or rework less popular aspects
2. Potency and/or uptime nerf on “problem” aspects
3. Buff specific exotic armor that have synergy with less popular aspects
So the article that mentioned this is kinda vague but the fragment nerf might only be for Prismatic. If that’s the case, then fragment nerfs aren’t a terrible idea as it would just affect Prismatic and not the base class. But it’d still be more of a bandaid fix imo