Taking 2017-2021 learnings to 2016 F1 cars

[Javert]

Suppose we take the 2017-2021 learnings and have to build a "2016" F1 car (with 2016 tires)

Which learnings would be useful?
Is anything learned on the side structures of the sidepods also applicable to 2016 cars?
Would "the cape" still be the solution to go to manage the front flow?

Would they produce longer wheelbase cars (e.g. 3700 mm) also in 2016, using the advances in weight reduction, or 2016 wheelbase (e.g. 3500 mm) was fine for 2016 rules?

[jjn9128]

Teams are constantly learning. Narrow noses are now "the thing" all the teams need to have over the "thumb" extensions. That's as much a structures thing, passing the crash test, as an aero thing though. The cape, I'm not sure, the front wing rules were less restrictive so flow conditioning-wise was easier, but also the diffuser and rear wing was smaller so adding more load at the front of the car might not be so beneficial - though you could trim out the front wing to compensate.