I think Contradance takes such a long time to resolve because it's so powerful. If it resolved any faster you'd be able to reactively Guard break/ cancel Resilience on multiple players, rather than having to coordinate well with allies to do so.

Being blown up or eating a timely stun to prevent extending the Charm is intended, and it means that Contradance is a challenging LB to execute well. It's got a huge range of outcomes.

On the short list, don't be the first player to start an engagement if you're leading with Contradance, and try to combo with allies doing stuff that will be Guarded, Purified, or limit enemy movement.

Oh yeah, and make sure your team is ready. Nothing is sadder than hitting 5x4sec Charms, nailing an entire Honing Dance, and then the enemies just Recouperating to full because no one on your team realized you were doing it. This is way more demoralizing than just immediately getting clapped when you start it. Who knows why your DRG was hiding in Guard right next to you...