Not 100% sure if this will work, but there is a way to ‘systematically’ remove the bottom safari bar with your meta viewport. Safari has a version called “minimal-ui” which removes the bottom bar.
Perhaps hiding it will let the phone think the user is constantly on the page and you will only need 1 click.
<meta name="viewport" content="width=device-width, minimal-ui">
From my understanding, what happens is, as you start scrolling the safari nav is set to hide, but when scrolling it’s almost as if you aren’t “actively” sitting on the page. So you have to “click back onto the page” then click your navigation.
In theory, running minimal-ui may keep the browser from thinking you aren’t on the page actively.
Hope this helps!