C’mon ShZ, that’s not what a BNB is all about.
And of course there’s no right amount of dates, even in the more yeshivish circles it’s important to take your time. Just don’t do it too much too often. A chosson and kallah aren’t bf and gf, and while they should spend time together doing things other than making their plans there really should be some boundaries. Any responsible mashgiach or mentor will say this.
Again, OP referred to “mainstream yeshivish circles.”