best way to timewarp sims?

[Chris Johnson]

I'm animating/simulating an explosion. The art director wants the initial
explosion of elements to happen at real time then 3-4 frames after the
explosion everything go slow motion. I've tested baking out the cache and
re-timing the caches in the Animation mixer with pretty good success. Is
there a better way or maybe some kind of remap node you can put as an
executable at the end of a sim? Or do people tend to over sim/render these
things really long and then time ramp them in comp?