A few users here have dabbled w/ the modifying the PCM signals, which would unlock an entire world of options for us. Road Race Motorsports has a piggyback ECU for the Mitsubishi Lancer that miiiiight work on our engine, but no definitive "yes" yet.
Quick history lesson: the 2.0/2.4 engines used in the Patriot/Compass were developed in conjunction w/ Hyundai and Mistubishi, and the same basic engine architecture was used across all three brands, and thus, there are likely many interchangable parts.
So, if we can get the computer to play nice with accepting modifications, we can start looking into things like hotter cams from Mitsu Evos, forced induction, altered displacements, etc.
The two really big questions are, 1) how deep are your pockets? & 2)how tolerant are you of being the guinea pig?
At this point, all you can do is work on de-restricting the breathing so the engine doesn't have to work so hard. Otherwise, the performance will remain the same by-and-large.
I will say, from experience, that removing the intake duct/battery cover seems to improve low-end torque, at the sacrifice of some power up around 3-4k. Also, the intake sound is louder, to the point that you can hear when VVT kicks in (yo). This may or may not be a positive for you.