Currently multiply markup defaults to the overall scale of the page, not the viewport scale.
Suggestion would be to have the option to use the viewport scale when using the multiply markup tool.
Well spotted @David Cutler. The multiply should really work using the scale at which the markup is generated.
Agreed @Vince French. I was surprised when I saw the multiply tool didn't recognize the viewport. Perhaps it is something that was simply overlooked in the development phase? At the same time there may be a strong case that was made to not have the multiply tool recognize the viewport. Perhaps it could be an option on the multiply screen? 😎