"Whether it’s the drivers, the engineers, or how they packaged an engine into the chassis, it’s always good to have that experience back," Taffin conceded.
"But it’s also fair to say that these guys are professionals and they are not disclosing any numbers or anything like that.
"So it’s not like you still have the drawings, the numbers, and things like that. Yes, it’s good to have but that’s not going to bring us where we want to be."
On the back of a dismal 2015 season as a supplier to Red Bull, Renault has ramped up its efforts to secure reliability and increased performance for its hybrid power unit on the eve of its return as a works team this year.
While substantial progress is in the cards, the French engineer remained unwilling to quantify its performance step, particularly against Mercedes' benchmark engine, acknowledging only that development shall be gradual.
"If we were one second down last year, maybe we will get back three or four tenths. That’s the sort of thing we’re looking into. But again, we’ll see what we’ve got at testing and races.
"There is a stepped programme but the programme is made for 2017. Obviously, we’re racing every other weekend in ’16, so if we can put some more performance, we will.
"For 2016, we have to be humble. We want to finish races. We want to be quicker and quicker. We’ll see how we develop that strategy. But it will be based on how we get to next year.
Taffin also revealed that Renault's early 2016-spec unit will not be very different from the one which was used at the end of last season.
"Basically, we’ve kept on developing the specification we had for the end of last year. It’s just ongoing development. It’s going to be different. It’s mainly ICE and turbo.
"The ERS systems are under control and where we wanted it to be at the moment. It’s not the big part of what we have to work on."