If you need a 9 1/16″ tall opening, just include that request in the order notes at checkout (credit card screen).
Do not place this in the Notes/Room Tag/ID fields, as those have limited character space and are not reviewed until the order is already in production.
Small dimensional adjustments are no problem and we’re happy to accommodate those. However, if you plan to modify every item in the order to sizes not listed on the website, that won’t be feasible. As an example, we recently had a customer place an order and then send a spreadsheet with dozens of post-order changes. The request was so extensive and complicated that the order had to be canceled to prevent errors.
In short: A few changes are fine—rewriting the whole order is not.