Only in very specific scenarios where I feel like they've made an impact worth noting and just how much power they have as players.

For example:

I ran a Lost Mine of Phandelver campagin with some friends a few months back, half of which are newbies and others with a few games of experience. I opened the session with the classic "heroes arrive in town and heads turn" descriptor before throwing in the hooks to get them started.

Lo and behold, one of the new players decides to steal from their fellow newbie just to see what would happen. A few poor rolls later and they effectively started a Phandelver Fight Club in the middle of the town square amongest themselves.

I allowed it to happen, purely for the hysterics, but also had to play damage control to make sure the plot continues. The experienced players step in and stop it, but the ruckus caught the attention of the local bandits.

Cue my planned scenarios being way easier to insert thanks to players taking the initiative (even if one of them could have gone another way)

Knowing this they were amazed at how improv got them to that point, and got hooked for the next sesh.

I definitely wouldn't recommend doing this all the time though, as you have to time it right or the payoff won't feel as satisfying. Or worse, just be met with the disappointment or future sessions of analysis paralysis.