Strange issue with high-res icons for scalable UI's (Maya 2016)

I´m currently adapting the UI of a tool to Maya 2016 and I want the icons to be scalable.
This is covered on the Autodesk site here:
http://knowledge.autodesk.com/support/maya/learn-explore/caas/CloudHelp/cloudhelp/2016/ENU/Maya/files/GUID-F2900709-59D3-4E67-A217-4FECC84053BE-htm.html

Problem is that this doesn’t seem to work for me unless the UI is written in MEL.
With a MEL UI, icons are picked accordingly to what the user has specified under preferences (under interface scaling).
With a Python UI, the largest (200%) icons are always picked.

Any way around this?

EDIT:
Seems that this issue occurs when there is no default icon available.
For MEL, you can have files like this:

myIcon_100.png
myIcon_150.png
myIcon_200.png
myIcon.qrc

…and it will load the myIcon_100.png by default if the interface scale factor is 100%

With Python, you are required to also have a myIcon.png file