Elliot,
your experience comes through loud and clear with these straight forward suggestions. In the future I might consider adding a similar feature to a public run modular display, with a shorter timer, like maybe 5 minutes. On a dedicated loop that could make thing interesting and cut down on the continuous roar inside a modular display.
Thanks for posting, and to the OP , this is an interesting topic. Post some pictures or video of your progress please.
Jhz