A bit disappointed that the new Outlook plugin still does not support DPI scaling for high resolution displays. The plugin is unusable on my laptop.
We are sorry to hear that. Improving all our apps for high DPI screens are on our to-do lists now, so hopefully in not to far down the road that will be changed.
Had also a post about it: https://todoist.com/Support/show/29433/
I added a screenshot to proof it is not tied to the scaling of IE as mentioned in the reply from todoist.
Same issue. Windows 8.1 app is unuseable.