The ej207 specC( the one I have) supposed to have different cams and stuff, actually it's not very laggy. By 4000rpm boost starts build and fast, B4 5000 fullboost in 3rd gear, then full power to 8000rpm. It's very nice.
About the tune, as I want it to last as long as possible, I'm going to lower the boost to 24psi, and keep it same way with lower boost at lower rpm and make it increase to redline.