On your boat, Patrick, a nacra 6.0 boomless design with a mast rotation inducer instead of a mast rotation limiter. I would try to sail with the rotation cleats fully uncleat under spinnaker. I venture that the hound fitting and sail pressure with rotate the mast far enough under spinnaker. And nothing is more bad then to gybe and forget to release the rotation inducer.

Note that we on F16's have only mast rotation limiters and we only uncleat the limiter lines completely to get up to 90 degrees rotation. So we are not setting any mast rotation under spinnaker. We are just uncleating the line when rounding A and have the mast rotate freely under the loads.

Wouter