Sure, the reflow can be disabled in the settings, but that's a lot of taps.
So, a shortcut to enabling-disabling reflow would help some.
But a better solution would be, as described above, a way to enable/disable the reflow just for the current page.
So one could have their preferred setting of normally reflowing/not reflowing, and a way to toggle for the current page.
I would adjust my setup to have reflow disabled by default, so i can zoom just to enlarge images, without breaking the site's layout.
And with a double-tap (or long press or ...) it would zoom to my desired font size and do reflow for a perfect text reading experience.