Improved HiDPI Windows support just like Photoshop 19.1
Essentially do with Illustrator what you've done with Photoshop (https://theblog.adobe.com/photoshop-releases-version-19-1-selections-improvements-advanced-support-windows-high-density-monitors/). That is "[offer] a full range of choices for UI scale factors from 100% through 400%, in 25% increments. [... A]utomatically adjust itself based on your Windows settings, making it simple to set up."
Luís Camacho shared this idea