At present, getting to your shopping list takes a bit of time and tapping that is really not necessary. I would like to suggest that when you tap the "Lists" option on the sidebar menu in the Alexa app, you would have the menu simply expand to show the actual lists under the "List" menu option. So, for example, the sidebar menu would expand to look like this:
--- <User Defined List 1>
--- <User Defined List 2>
Then, with a single additional tap, and without having to wait for the list selection page to come up, the user is taken to their shopping or other list much more quickly.