Broken exhaust manifold tab / ear...

This is why I use the perforated Felpro exhaust gaskets, haven't had a problem yet. My opinion, if they skipped gaskets when new or used a shim gasket, remember, the manifolds were new then. They have a history of warping over time. For my money, Felpro took that into consideration when they designed their exhaust gaskets. Be careful when torquing, and recheck them after a few heat cycles. I do not know what the Reflex gaskets look like, so no comments on them.
You can check for warping better with a straight edge. If something doesn't look or feel right, stop.