Even if the weight was the same, the rigidity would've been massively improved by the cage. That's a huge performance boost.
No chance that was a standard engine, Honda had too much relying on the time to take a chance. Blueprinted at the very least, if not with the wick turned up. Look at the lengths Seat had to go to just to catch the Renault, Honda haven't produced anything decent for years so to expect them to crack it at the first attempt by playing it 100% is a tad naive.
Even if they'd come within a couple of seconds that's would've been a great achievement, but too many people buy cars based on Ring times these days sadly, so it was either beat the time at all costs or lose sales. Maybe I'm just a bit cynical, but that's how I see it. Same way I don't think the P1 beat the 918 round there, there's too much face to lose if you don't trump it.