S40 t4 phase 1 ecu mapping

Hi all I'm andy and back in a t4 after a couple of years.i know the phase 1 ecu mapping has been asked before but there's conflicting views and old threads..iv done a search and there seems to be a good few tuners that can do the phase 1 ecu these day e.g Celtic tuning
So my question is......has the tuning changed on the phase 1 ecu is it as simple as any other ecu?
Plans are
Coilover
Full system with cat off
Filter
Up boost to 1.5 ish
It's a weekend car not daily and I'm also building a 385 small block v8 capri so don't want to go over top with t4 just want a good punch out of it
Any info would be great
Thanks andy