Thing is, an engine dyno for example, is more accurate than you could typically show with any aftermarket ECU.. so the question of "can you set them up the same on an engine or chassis dyno", the answer would have to be yes.. (assume a steady-state chassis dyno)..

Ultimately though, an engine dyno is better. It's a much more controlled environment and is ideal for R&D & mapping.

As above though, everything should be checked thoroughly on the road too.