Hi, witch resolution and dimension have your display? If the dimension to small for a high resolution (5,5“ 1920x1080 or so) then the best way is to scale the chrome generally. I have do this for a Waveshare AMOLED otherwise all fonts to small.
This is possible in /opt/volumiokiosk.sh. Important: Duplicate a complete line and change only the text:
(I use for 1920 on 5” =2.4)
The autoscale for a to small cover I’ll look. All my covers are 500px or 700px, so I haven’t this problem. I give you a response, if it possible.
edit: I can’t reproduce your problem with to small covers. I have create an 300px cover picture and look, it was scaled to container size in landscape mode. In portrait mode on the left and right side a bit space. But the portrait mode isn’t change it is original.