Is it worth it?

I PvE as DW Frost. I literally only do 5 mans and the somewhat random LFR. I do re-forge for hit/expertise cap when I do LFR though.

Buuuuuuuuttt anyways.

My question pertains to waiting on KM procs. If all of my runes are down and I have a full or near full Runic Bar and KM procs, should I wait for my runes to Oblit, or should I just FS?

Is there an exception, like, if there's less than 2 seconds left before you can Oblit then wait but if it's longer then FS?

Thanks.
will the obliterate push you over rp cap? frost strike.

is the obliterate coming up within the next gcd? if not frost strike