The Cap 10B has had some spar failures, but generally caused by overstressing either on the accident flight or a previous flight.
The one I fly has a recording G meter, and club-imposed limits of +4.5 and -3g. Woe betide anyone who exceeds them! In France, parachutes are mandatory for aeros. Despite the monitoring and low G limits, I'm not sure I'd be happy to aerobat the Cap without one.