But the only way to magnify the place where you just tapped (that is, inline, where the magnification shows where the text is on the page) as you drag would ess

But the only way to magnify the place where you just tapped (that is, inline, where the magnification shows where the text is on the page) as you drag would essentially be to not move the cursor as your finger moves (i.e. wait until your finger gets out of the way). I don't even understand how this would work if you're dragging up (going to a previous point in the text).