Offshoreonly.com - Cracking Vent Louvers

I bought this boat (2003 baja 302 boss) a couple years ago and it was just starting to crack around the vent louvers on both sides at that point. 2 years later and 100 hrs of Lake Superior and the cracks are almost completely around, it's time to fix. My question is has anyone else had this problem? They appear to be epoxied in, then gel coated. Am I better off grinding relief down the seam and using a silicone/urethane to fix this, or vinyl ester resin them and re-gelcoat?

https://cimg3.ibsrv.net/gimg/www.off...98b473877a.jpg

https://cimg2.ibsrv.net/gimg/www.off...e9e700a95d.jpg