There's a delay in the messages that are put into Dyamic Quarantine, but not that many messages end up there. We've had it enabled for multiple years and haven't seen any issues with it. You can also look at the contents of the Dynamic Quarantine queue at any time and release (or delete) any emails that you want. I'd suggest enabling it, reviewing the contents as it works and getting comfortable with what it does. If you think it's delaying too much legit email, you can always turn it back off.