Honda Power Unit Hardware & Software

[mzso]

Come on, there's a lot to blame Honda for, but this isn't on Honda. They didn't even have a chassis to test integration with just before the start of the season, and it got sorted once they did, in Sakura.

Cowell as a lead at Aston, and ex-Merc powertrains, was probably best-placed to smooth integration, schedule, oversee progress etc. Perhaps his get-out-of-jail card on this was the super-late car build-up, which was probably due to when Newey arrived, and the late design phase.

I doubt that Mercedes had tested their PU in their buyers' chassis'. Particularly Williams who were also late. But none of them had vibrations.
And the "got sorted" part apparently includes running at reduced power and extra weight to dampen vibrations.