Working on theory crafting lists to hunt down the IG's that I've had difficulty taking out. So far my thoughts are with

2x Delta Defenders with HLC - Lots of dice being thrown at them, something is bound to get through, worked on Soontir.

Wedge and Corran both with Outmanuever and Engine - Take away their agility and something is bound to get through. Not sure how to fill out the rest of the list besides FCS and R2D2 on Corran

Dual Defender - Rex and Vessery Rex with PTL, Vessery with VI, both with HLC, Prockets, and Engine Upgrade, Once again, lots of dice, something is bound to make it through.

Rex and Shuttle - Rex with HLC and Shuttle with Vader and Fleet Officer to make sure Rex gets 2 Focus a turn, not sure how to fill it out.

Are there any other ideas I'm missing that doesn't involve Wave 5 or 6 since I do not own any yet and won't have them by Regionals.

Swarms have fun with a numeric advantage.

Just run some stress mechanics. Some variant of Panic Attack (B-wings with E/2 and Tacticians and an R3-A2 carrier) should rip through double-IGs. You deny them actions, possibly making their Advanced Sensors a waste of points, and lock them out of the S-loops and K-turns that they so heavily rely on.

Tactician wings would work, don't have the Transport though for the Stress bot.

Rexler, hlc, predator

Boba Fett, hlc, predator, fleet officer.

Enough dice to burn them down, enough action economy to apply a ton of hits, enough arcs/maneuverability to make their life suck, ps 8 to shoot first.

A friend of mine developed a really nasty Dual IG-88 list, that has me scratching my head for a way to beat them. The list he made ran (IIRC):

IG88B/C

Accuracy Corrector + Predator + Mangler Cannon + Autothrusters + Seismic Charges

Multiple offensive rerolls, and if he didn't like the dice, he could just cancel everything for two hits. I got torn apart, though that had a fair amount to do with my list running two turrets, and my dice being colder than Pluto. Fickle dice aside, I've been struggling to come up with a way to beat these bots. My current thoughts are to throw an Autoblaster + Opportunist + EU + UA Kavil at them and see how they fare.

I've had 100% tourney success using stress and ions. They fall apart like interceptors without actions.

I have only played a dual IG-88 list once so far, but I did get a good win. I used Rear Admiral Chirpy w/ VI, Yssane, EU and Navigator and Rexler B w/ VI. The VI really helped, as did the Navigator. Stay out of their arcs and fire at them.