I've been struggling with this issue for a really long time. HDMI-Scaling doesn't work on my 2048*1536 //30hz progressive monitor.
My pc has the latest crimson updates (17.4.3), and the HDMI-scaling option is missing, it's not there!
When using my intel hd graphics 4600 instead of my r9 390 in the same PC, it does work in the intel settings.
I don't know if you are going to release a bug fix for this, but in the meantime could you tell me what the latest drivers are that do support scaling on the given resolution&refresh rate?
GPU: R9 390
IGPU: HD 4600
Monitor: samsung LTL097QL01-W01
OS: WIN 10 PRO