Legend has it there were variations. How to determine this sort of thing from our perspective is a mystery but I've seen enough P&P ECU's on the wideband to know that some work well, others not so much.
I haven't seen anything from Blitz themselves to suggest a 'tailored' approach to ordering an ECU to suit an individual car (well none that I can remember) but I've seen them sell turbo kits with an ECU as part of the package. This would make a lot more sense than introducing the variables of turbo/cooler/fueling/etc/etc involved. Info is very thin on the ground unfortunately.
From memory Grzyor on here bought a K1 kit that was like that.