@Cathy Sorry, I might've worded my question wrong. What I was pondering is if its even worth using Ramegid Zero on Te/Hu instead of just normal attacking and keeping up Zanverse in group situations.
Basically I'm pretty sure its not worth casting uncharged, but not quite sure if the full uptime damage charged cast is worth it + the extra time that it takes to switch back elements... and for the moment I lack the mechanical insight to do the math myself.
EDIT: did some Rockbear testing and napkin math. From eyeballing numbers, to me it seems to be worth casting fully charged + switching elements if I can guarantee ~8-10 seconds uptime on a single target. Roughly half if the target is weak to Dark. Naturally this isn't accounting for the 15 points that otherwise would be invested in raw stat skills instead of Dark damage.