We have our own component library designed @1x (100%).
It works well with web and some rare devices with screen densities of 1x.
However, we have a designer who is constantly working in projects that target devices with larger pixel aspect ratios, like x1.5, and x2. To facilitate this difference, this designer creates bigger artboards and resizes the components accordingly. All of this hassle is done so that the developers can see correct measurements in the cloud prototype (element sizes, font sizes, margins and paddings). Usually Dev's don't need to download any assets. Just measure stuff.
This made me thinking, that wouldn't it be easier if the XD's cloud environment allowed the developer (or any user) to change a multiplier in the UI, and then see all measurements multiplied by 1.5 or 2? Similarly like you can now change the unit of measurement, you would have a dropdown with options for x1.5 and up to x3.
This would multiply any measurement and even calculate the font sizes according to this multiplier.
The benefit for all our designers would be that we could all be using the default artboards and would not have to resize the components.