I have megasquirted 3.0L, a decent sized turbo, 18psi of boost and maxing out my 550cc injectors I get 240RWHP. It can't get much worse than that. At 8psi I made 170rwhp. So, you're doing better than me, I'd say. Long story short one cylinder doesn't have a whole lot of compression and it wasn't tuned.
I think Megasquirt would be the way to go. Yeah, it's a pain to setup if you've never done it before, but once you wire in everything you're done (except for tuning). It's pretty straight forward for these engines. Lots of people have done it here and can help you through the way.
One thing you could do, right now, is remove the rising rate FPR. Those are just band-aids that will get you running, but going very rich under load.