The tyre profile will certain affect the steering but I'd expect a more direct response from the 65 and more push and resistance from a 60 which is more likely to make the bike run wide.The thing about a bike standing up on the brakes is it's usually the rider who instigates it and by that I don't mean you are to blame.I'm guessing you sense there isn't enough grip/steering to continue braking and turning in so one has to go and the uncomfortable feeling makes you choose slowing the bike rather than letting off the brakes and taking your chances with more entry speed.You mentioned the 636 is your wife's and it's running similar settings ,is that just for the forks or both ends?Your basic problem is either not enough weight transfer to the front or it's returning too quickly.I'm guessing here but have you by any chance lowered the rear on the 636 to make your wife more comfortable to reach the floor?If you haven't then try letting some preload off the forks(mabye 2-3mm)at a time and go for a test