Argh, right! There would be a problem with reset=target in castsequences....

..sry, i was writting the above from sratch, i personaly use this the other way around, meaning:

I use the actual target for the dps-target, and focus for cc.
Defining who is the leader I do by using a modified ftl-aproach (see:Focusless, targetless, 'leaderless' setup. )

in this aproach reset=target works, cause i'm actual targeting the mob to dps.
Do you use keyclone? -Perhaps a similar setup would work for you?
-personaly I find it very usefull for switching the leader "on the fly".