LAN is dead. We killed it with our high-speed internet connections, always-online consoles and Steam.
And even before that, casual LAN parties were a hassle to organize and set up logistically. They happened, but...
Haha, that was meant to be super/hyper cardioid! Both just a more intense pick up pattern than typical cardioid). Perhaps that could be a solution, although at that point I'd probably rather just have another headset on over my IEM's to simplify everything. And LAN's like MLG mainly!
Super AND hyper! DOUBLE YOUR PLEASURE!! MIC HYPE!
And sure, you could get some closed headset with mic that fits over IEMs, but you're gonna hate the feel, and it would be even more complicated than the DIY method.
I'd love to get into MLG, but I doubt they'd take someone who is 28. Over the hill!