It's better to be cautious than to crash, of course. And the trouble with being a nervous descender who's trying to keep up is that one enters the corner fastish, gets uncomfortable and then hits the brakes in mid-turn, which is exactly the wrong moment - often less safe than trying to make the turn at speed. The conventional advice is to get the braking done before turning in, and that's pretty sound for starters. Really good bike handlers use trail braking, like on a motorcycle, so that they spent the least possible time at the slowest speed. It's good for cornering in racing, too. But it's a pretty advanced skill, I'm not all that good at it myself.