As long as you're reasonable and negotiate with your flatmates, yes! All types of accommodation would require you to be let in by your friends or vice versa, but there's no curfew. This is pretty standard across all types of accommodation offered by the University. For example, the Vale is a public park and there are many different accommodation blocks on it - I lived at Aitken and could visit my Chamberlain friends whenever
It's a different case when it comes to parking though, you may need to negotiate with the accommodation block if your visitor were to use accommodation parking for an extended period of time.
Hope this helps and feel free to message me if you have any more questions with regards to student living,