[EricH]

For those of you saying that a downforce would be legal:

I'm 99% sure that it's not legal. The wording in the rule is clear: if it increases traction, it's not legal. The idea is to increase the normal force, which increases available frictional force (not friction), which increases traction. That's increasing traction, which is illegal.

The other 1% says to ask Q&A when it comes online and see what they say.