The flaw can be fixed but will it be enough who knows. There's a good half second they can find if they nail the bargeboard, shame it's the last year we'll see them. Seems almost a waste.
In terms of packaging the Renault engine is the worst of the 4, and the packaging and the bargeboards are critical to downforce. If both packaging and bargeboards improve the Renault team could take a step forward because believe it or not, they have the best suspension on the grid.
The problem with the Renault chassis is evident when compared to the McLaren chassis. McLaren just has more attention to detail than Renault, the McLaren craftsmanship is better than what Renault is capable of. Perhaps there's too much micromanagement going on, they try very interesting solutions, but they focus too much time on one or two aspects instead of looking at the car as a whole.
Fighting McLaren should be the objective, that is the most objective barometer because everything under the hood is the same. The chassis that surrounds the power unit and the team operating it are the only difference.
McLaren builds their own transmission, their own chassis, suspension, aero, fuel tank etc. They are doing a better job than Renault on that end along with the sporting side. Renault now has a very strong driver pairing, this is a big test for them and the rest of the team. So a lot to play for.