There are a million Steve's, some are even willing to do "tunes" or "touch ups" for as low as $50. They will happily talk to you all day and tell you everything you want to hear. Something I learned several years ago -- when you actually know something in this industry, you don't share it. If...
Anything over 210-220whp (which requires an RBC swap) is unrealistic. I watched a ton of these "220-230" claimed cars run 14's and trap 98 mph while at the track... 98mph == 190whp.
I provide a map with the correct map sensor setting if you tell me which one you're using (I have a notes field for mods during tune purchase). It's a simple setting and doesn't change the basemap. You can even do the same on the KW basemap, just toggle the setting from stock to 4 bar. However...
Your mechanic needs to check fuel pressure at the rail. Everything you're describing points to a mechanical issue. The one *constant* variable we have here is the base map, it's started DOZENS of cars with the same kit, same injectors, same pump, same map sensor.
Your motor isn't getting enough...
Yeah... that 3-4 hours is for me... and I've done a ton of work in this engine bay, so I know where all the odd bits and pieces are and where they go back after I'm done, lol.
One thing I didn't mention, the RBC swap is a total pain in the *** too. It moves the TB to a whole different location and the harness doesn't reach. You have to undo the big plastic clip holding all the wiring on the side of the head. Definitely a 3-4 hours shop time to do it on a customer's...
I preferred a 13+ to save me some time on tuning. Beyond that I didn't care, since nobody stepped up, I have a local gent that is an RSX customer with a 2012 9th gen who purchased a FR DP & exhaust and is coming in for testing. He's a little closer than you are, hopefully I'll see you someday...