In case you are needing a fast answer to your question…
(Here is the question for reference) https://vexforum.com/t/question-about-starting-positions-for-robots/28865/1
Yes your preload can touch a gray scoring post. However it cannot breach the field perimeter.
Proof of this can be found here:
Check out our reveal video. We show our autonomous at 1:18. It is a perfectly legal placement of the cube against the post. This is commonly referred to as a “cheater cube”. The judges doubted us at our state competition so we made sure to have the above forum link ready to show them. Once they read it they understood and allowed us to do it.