In ArcGIS Pro, it is possible to set "scale based symbology", e.g. so that within a certain scale range you could have a different size. I tried then exporting that to a mobile map package and consuming in the runtime, but the runtime didn't honour the different sizes.
Two questions, should it honour it? And if not, is that on the roadmap for any time in the future?
Paul,
Symbol Scale is not currently supported for feature layers and it is on our list to address for a future release.
One thing you could to that may work for you, is to create a vector tile package of the layer, the scales will be "burned into" the VTPK. Then use the VTPK as a layer to get the desired display. If you need access to the actual feature class, include it as well with 99% transparency applied. The 1% won't be visible, but will allow you, for example, to tap it for a popup if needed.
Mark