Despite him threatening to drop me, I had absolute faith in Wow after the first stop at a junction in Fulham on our test ride and didn't put a foot down unless instructed to for the whole of the Dun Run - I think maybe twice apart from when getting on or off. At the time I think Wow was probably the only tandem captain on the forum that outweighed me. He did comment that my being a shortarse helped as it at least meant a low centre of gravity
Stoking for Martin109 I discovered that, although I outweighed him by quite some margin, I had to trust him to hold the bike and me up when stopped, as I couldn't get even a toe down getting off the saddle - the standover height on Bertie is just too big for me.
I wouldn't want a brake under my control. I don't think I'd trust a captain who would trust me with one. Pedal and not even need to follow, that's the joy of stoking for me.
I'm not strong enough to old Mrs. Wow vertically on the tandem. She always puts a foot down when we stop. Life would be a lot easier if she didn't have to. Crinkly, on the other hand, I found fairly easy to hold upright. All that extra seatpost makes an awful lot of difference: Mrs. Wow is not just tall, she's got disproportionately long legs.
Nutkin, who is about the same height as Mrs. Wow, has a more normal torso:leg-length ratio. I can hold her up as well.
So far as braking is concerned, I find that our V-brakes are fine, but I have to anticipate in the wet, even with tungsten carbide rims and Swissstop blue. There was one hill a couple of weeks ago on which I thought the bloody thing was never going to stop. We weren't going quickly, we just didn't seem to be able to slow down, although of course it did eventually.