You wont be disappointed with your flap, honestly - it's great. And yes, even if Geoffrey and Millie slipped out by accident, once the curfew mode is set they'll still be able to get in, just not back out again.
We use ours all the time on that setting, although occasionally it means we hear Dickie battering at the flap to be out at 4 a.m instead of 5 a.m. which is our designated opening time.
Seeing as the clocks go forward this weekend, we're going to move the opening time forward too to 4 a.m., so we dont get woken quite so early with a demand to be out.
Ross was indeed a bit too "comfortably upholstered" to get through the smaller sureflap
but he manages fine with the pet door. (And he's not plumpitty, it's just sorta distributed differently!
)
Actually, I think it does depend on how your pet's weight is distributed, and how they feel about getting through gaps. One of our neighbours who saw our flap and was having similar trouble with her cats being bulled got the smaller flap, and both of her kitties fit through it. And considering one of them is very fluffy and on the large side, we did have our doubts.
They do say that the flap works now with biotherm chips too, and I have to say the people who make Sureflap are brilliant - register your flap on their website when it comes - each flap has a product code, and you key it in to activate your warranty - doesn't matter whether you bought it direct from Sureflap or not. They put customer satisfaction at the top of their priorities, and I think it's a rare company where you can buy with such confidence.
You'll feel so much happier knowing that just your cats can get in, and they'll feel a lot happier too. It's great seeing their faces when they realise bully cat is stuck outside and can't get in.