There is an extremely simple solution to the problem (I think). Purchase a set of tire savers. Honestly, i've NEVER had a flat while using tire savers on slick road tires. Caveat : I've never used tubulars, however.
When you get your first flat, simply bend the tire savers into position to rub against the spare tubular. You might incur a 0.25 mph drag penalty, but the chance of getting a second flat will be so close to zero, that others in you group will probably exhaust their spare tubes before you get a second flat on your backup tubular.
- Don Gillies
San Diego, CA