Your market may vary, but it is probably cheaper to just "switch out" the 30 than to remove it, and deliver a different size having to use a different truck.

Deliver pizzas on nights and weekends.

Most contractors I dealt with would just try to charge the most money they can and not try to point out ways that can reduce costs while delivering the finished expectation of the product )which varies, i,e, a $200k single family home rehab vs. $1.5 million mansion rehab vs.4 unit multifamily rehab).

I commend you on your expertise and contributions, but take offense to your original statement or how you delivered it. 

Contact an attorney and get a cease and desist letter prepared and delivered to them.

Could someone fill me on who's area of responsibility the creation of these plans belong to and who I should approach to get the plans delivered?

Because the contract calls for you, the holder of the LC, to deliver title, you must have title in order to deliver.  

If it were, people would pay minimal amounts on paper and deliver the balance in cash to avoid the taxes.

Ask them to front the cost and once they deliver materials and show receipt you write them a cheque?

Do I deliver it in person, meet at a Title company???