Does it impact admissions chances whether you attend webinars or info sessions, etc? I’m applying to 10 schools so it would be a considerable timesink to do that.
It depends on the school. You can check their common data set to see if they track demonstrated interest.
The OP is asking about boarding schools, all of which consider demonstrated interest.
The OP’s question can’t be answered in a vacuum. If they haven’t visited the school, then they’re useful. If they’ve visited already, maybe less useful.
So if I’ve done an in-person interview and/or summer tour, not that influential?
I think you may need to reframe this. The isn’t a test created by the school. It should be a little more organic.
If you said you were interested in STEM and the school has a webinar on its STEM offerings, you would probably be curious – because you are interested in STEM, not to “show interest”. And presumably, this would be more in depth than what you saw on a summer tour. You would get to see faculty and students and assess fit, etc.
It won’t count against you that you don’t show up. However, it also – in its own way – is showing the school a certain lack of curiosity. A lack of curiosity that is probably shared by most applicants, btw. But there will be applicants out there who are really excited about some of these webinars and learning more. That is usually viewed positively.