Is it legal for the preloaded cube to be touching the skyrise base?
We ask you to please thoroughly read the VEX Skyrise Game Manual and to please review the Q&A Usage Guidelines before posting in this forum. Specifically, please quote the rule or definition that your question is referring to. In this case, the answer to your question is right in the definition.
Let’s take a look at the definition of Preload from the VEX Skyrise Game Manual. I’ve bolded some text for emphasis: