I'd defer to someone on the Chromium team if they have any input, but Chrome is what I was using at the time (not too long ago) and there definitely weren't any

I'd defer to someone on the Chromium team if they have any input, but Chrome is what I was using at the time (not too long ago) and there definitely weren't any events firing for overscroll. It would be nice if they'd add notification about that, but it would be very difficult at this point to disambiguate between true overscroll and the animations that some browser/os combinations are displaying now. For such a niche use case (that really doesn't provide much benefit on non-touch pages anyway), I wouldn't be surprised if we never see it added.