We still need the ability to reference driven dimensions after 6 years of this being requested and acknowledged by Autodesk. Autodesk claims this is not rocket science, but a lot of work. I don't see how this is either. They locked the comments on the ideaboard about this topic without offering an eta to complete this. I don't see how this is a lot of work for a company the size of Autodesk.
Your solution does not work if the driven dimensions changes. The dimension referencing the driven dimension will be stuck with the old dimension - not parametric design.
Autodesk claims this is because they made some poor design decisions in the beginning of making Fusion 360, which of course is true, but still not an excuse for this feature missing. Just because dimensions are for some reason only calculated in one compute pass at this time, doesn't mean its too difficult to make a new type of parameter that can be based on a second pass. The driven dimension is always available for us to look at and reference manually. There is no argument to say that it would be too difficult to allow the software to access this updated dimension automatically in the parameter process.