toadog, welcome to iRV2.
I'm not familiar with the type of slatted awning you refer to, but the problem with awnings unfurling comes about mainly because the pawl that you flip to roll the awning in and out becomes worn and will not reliably prevent the roller tube from unrolling when air gets up under the awning. This can happen even though the awning is completely rolled up and the support arms are tightly locked up against the side of the coach.
There are a number of awning locks available, including some homemade versions, that prevent the main tube from unrolling.
HERE is one version that uses a spring-loaded pin. If you Google "RV awning lock," you will find more.