<GG18> + <SG11> Placing blocks in the park zone

In GG18, it says

Blocks may not be used to accomplish actions that would be otherwise illegal if they were attempted by Robot mechanisms.

My question is regarding whether it is legal to intentionally place blocks in my opponent’s park zone. As the park zone is protected during the last 20 seconds, would the blocks still cause me to violate this rule even if they were placed there ahead of time?

If it helps, the blocks would be placed in the park zone with around 30 seconds left, and they would come from a “box” fed by my robot’s sorting mechanism.

it’s legal, we have a similar mechanism on our robot