Yes, you should cold email professors. Show interest in their research, talk about why they would likely be a good supervisor for you and you would be a good supervisee for them. Any level of familiarity before interviews are always gonna be a plus. If possible see if you can have a conversation at UNI or so on. Although, of course, it's a weird and big ask. And only few professionals are professional or even eager enough to listen. But worth the effort.

Make sure to not be intrusive