According to IVA, if the projection sticks out less than 5mm then the edges need to be blunted. According to the aerocatch drawing -
http://www.aerocatch.com/updoc/Tech_...flush_dims.pdf if you use the ones that mount externally then they only stick out 2.5mm so should be ok.
The flush mount ones need a bonding plate so the bonnet would need to be less than 2.5mm thick.