Im mainly a paladin but i have this Shadow Priest i was trying a thing on. was on target dummys and noticed that i could do 2mind flay in betwin each mind blast so i made this macro:
#show Mind Flay
/castsequence reset=combat/target [nochanneling] Mind Flay, Mind Flay, Mind Blast
what do u think of that macro, it basicly casts 1 nonchanneling mind flay then a mind blast on current target, this is ofc just in stand still and nuke 1 target macro but still want some feed back if its good or bad in a pve situation, also have Power aura classic to show when MB is off CD so i can choose aswell when to use it
To add some specificity to the reason why it would gimp you is that you also have to refresh Vampiric Touch and Devouring Plague. Yes, casting Mind Blast is a higher priority if it's up, but refreshing those DoTs is higher priority than a couple Mind Flay ticks. So you could use that for some of the intervals of Mind Blast CDs, but you'd still have to have separate buttons for when you need to refresh DoTs, which just adds another button and makes things more complicated and it doesn't really help at all since that's the easiest portion of the priority to manage.
Now, I have seen some Shadow Priest macros that work fairly well, but they're pretty damn complicated, don't work well if they get interupted, and won't work at all when Haste starts affecting DoT ticks in 3.3.