The only way i have been able to replicate castsequence is to put in multiple /cast statements in order of highest to cooldown to no cooldown.

It will cast them in order, you will get the red message saying only macros with /cast sequence will operate, but the spamming it will cast the second or third spell without the getting the red message. Not sure what everyone else is doing.

I've also been looking for a nochanneling stopcasting macro, but i have yet to find it.