I haven't broken a string playing out for at least twenty years Will - I change 'em regularly! But yes, I agree, it would be a tricky operation under the circumstances you describe.

Not trying to be a Clever-Shit, but I'm very careful when stringing up to seat the ball-ends carefully, and not to force the pins in hard. Plus I've slotted the bridges on my Martins so I use solid pins. I also rub a candle over the shafts of the pins now and again, which helps when removing them.

There's a lot of good info on the internet from people like Frank Ford, John Arnold, Bryan Kimsey, et al.

Re: the Pinless bridge, my Lowden has one and it's nice not to have to faff with pins, but other snags present themselves - such as always having an envelope or piece of card handy to prevent the ball-ends taking chunks out of the finish when stringing/un-stringing! Otherwise they're great (providing they're glued properly!). :-)