EDIT, it’s not quite how I said in this first paragraph now I look at that page properly but you get the gist. It will guide you.
Well look you are right, some pages will take the reader a bit of time and be less good. I would imagine for that page there you’d get the two top triangles then each time you tap you would go to a number in the main page then the next tap would put you back to the key, then you’d go to the next number. It’s possible you’d get a zoom out between each to take the whole thing in.
But there’s an up side too: When I open the pages of the comic I always take in everything. That means that if there is action or something significant bottom right, I am drawn to see that before I read the events. The guided reading stops that happening - which means it’s at the end you get the ‘whole page’ view not at the beginning - meaning every panel is new to me until I reach the end of the page, and I like that.