Hi, echristoperj. Great question! 🙂
The short answer is that our architecture has significantly changed since the 2.x versions and masking of additional days of recurring events is only supported out of the box for the List-type views.
It would certainly be possible to craft a solution that would hide subsequent days of multi-day events for the grid views, but to do it smoothly would probably require some intervention with the query filters. I’m sure that “quick and dirty” hacks are possible. The problem is they don’t take into account pagination parameters, how many events to show per table cell (in month view’s case), etc.
Also, in Month View specifically, there’s no single overarching query, it’s 28-31 individual queries plus some more on top. It may be there is a smooth way to do it, but it definitely take some doing to take all the factors into account.
I’m sorry that I don’t have a snippet to offer you. Should you decide to pursue this on your own, please feel free to ask specific questions if you get stuck. We’re always happy to make sure you stay pointed in the right direction! 🙂