Better to use "reset=8" (or whatever your MB cooldown is if you've got talents invested there).

My (lowbie!) DD sequence looks like this:
[code:1]#showtooltip
/castsequence reset=8 Mind Blast, Smite, Smite, Smite, Smite, Smite[/code:1]
There's at least one two many Smites in there, but it doesn't matter because it goes back to MB after 8 seconds.

I prefer to use focus for CC / fixed cross-healing. I haven't bothered to solve that one yet, but I will, and whatever solution I use (the mod posted on this forum, a working variant of the multi-char follow macro, whatever) won't use focus. It's too valuable for that.

Still, if it works for you that's great