If you could do things differently would you be more lax or even stricter, or were your restrictions just about right in hindsight?
Also, it depends a lot on the kid, the relationship, etc. It was a fine line, these were important social interactions for them, but there was definitely risks to be made aware of and kids are famously bad at risk assessment.
So it was something I would monitor as best I could and check in with them on, but at some point you just have to trust them and hope any mistakes don't have overly severe consequences.