XD provides CSS for everything in the layout which saves developers a lot of time, so by not supporting relative units, a lot of tedious unit conversions still have to be done manually. In this respect using XD is no better than still using Photoshop for web design.
So why aren't relative unis supported in XD in the first place? Yes, I know that by definition the word "relative" means they don't have absolute values, but in practice every browser's default font size is 16px, and many websites have reset stylesheets that override this to set 1rem = 10px.
In my opinion XD should at a minimum
* allow designers to use rem in their designs
* use 16px as the base value for 1rem
* convert values between px and rem using that base value
* allow designers to set a different base value
* allow developers to view and export values in rem units
And it would be even better if XD could
* handle unitless decimal numbers for line height values, e.g. "1.33"
* handle ex and ch values which are computed from the font metrics
* handle em and % units using 16px as the base value, just like rem
* cascade em and % unit values correctly through the design, which I grant is probably a non-trivial task in a design program that has no concept of a DOM
XD provides CSS for everything in the layout which saves developers a lot of time, so by not supporting relative units, a lot of tedious unit conversions still have to be done manually. In this respect using XD is no better than still using Photoshop for web design.
So why aren't relative unis supported in XD in the first place? Yes, I know that by definition the word "relative" means they don't have absolute values, but in practice every browser's default font size is 16px, and many websites have reset stylesheets that override this to set 1rem = 10px.
In my opinion XD should at a minimum
* allow designers to use rem in their designs
* use 16px as the base value for 1rem
* convert values between px and rem using that base value
* allow designers to set a different base value
* allow developers to view and export values in rem units
And it would be even better if XD could
* handle unitless decimal numbers for line height values, e.g. "1.33"
* handle ex and ch values which are computed from the font metrics
* handle em and % units using 16px as the base value, just like rem
* cascade em and % unit values correctly through the design, which I grant is probably a non-trivial task in a design program that has no concept of a DOM