good question - cuz we still need to reflect the music :-)
our combos are mostly short (8 cts.), but if we're in one of the longer ones we usually do break off & get with the new tempo. I think it works better that way.

I'm such a bad moderator...I'm JUST now getting to this. See what happens when people get busy?

Anyhow, it depends on the combo or move, I guess, and when in the combo the tempo change hits. If finishing out the combo wouldn't really throw off the pacing too much, then a quick finish out may not look that out of place. There are some combos that I've done that look just as good when you slow them down, even though they're not designed for slow music, so they get slowed to match the new tempo before we jump on. However, if the move or combo doesn't work well with the new pacing and will look really out of place to finish it out, I'd rather just jump into a new move that goes with the tempo. It tends to look smoother that way, at least in my opinion.

my 2cts:

If you're dancing on the beat to music with regular time, this should never happen.
If you're dancing to odd timed music, you should readjust your movements or your music.

much love!
ali