I'm being told there are crush sleeves that go in the coil wells that I should have replaced. I'm not sure my engine even had them... Regardless, it's something to know for next time.
Also apparently the plastic valve covers themselves can cause problems with sealing with age. No surprise there. BMW and their damn plastic engine parts...
I lucked out and mine has been great since replacing the gasket, but if you're interested, there is an aluminum valve cover option. Here's that link:
VTT Modular Cast Aluminum CNC Valve Cover Kit