I got to put a box through it this weekend. My accuracy was a bit embarrassing. I can see it is going to take some practice with it.
I had one issue that came up one time. The trigger stuck in the back position. I had to hit the cylinder release and then then trigger popped back forward. Hopefully that doesn't continue. I am assuming it just needs some breaking in.
Shooting J-frames accurately tends to take a little extra practice but is entirely doable -- and fun. Also, as the action smooths with use -- or if you have the action gently smoothed by a qualified revolversmith -- you'll note a natural increase in accuracy.
However, the trigger should not be hanging on rebound, provided you're squeezing all the way back then releasing.
Might mean the internals need a cleaning and lubing; might be a bur or metal shaving (not uncommon when factory new) that needs addressing; or there might be a problem in the lockwork.
But it should not be happening and isn't related to break-in. See that it's attended to, calling in the warranty if necessary, before betting your life on that particular revolver.
Hope it isn't your original concerns realized, but also don't place too much in active complaint threads; they're in abundance on the Internet, while active "I'm happy and have no problems with my revolver" threads -- common though that experience is in the world -- are at minimum online.
For what it's worth, despite a happy abundance of various S&W revolvers, it's a common 442 that does virtually all my heavy lifting and has for years, with zero issues to date.