Emulate low resolution Display in Qt

Hey there,

I’m in the process of building a little thing with a PiSound/Teensy and an OLED connected to it, but would like to do some prototyping first (testing different screen resolutions/sizes). Later on, it would be super-cool to re-use the GUI stuff I wrote in some way to the display via OSC. For now, requirements would be: Writing StaticText and drawing lines to a Qt Window and being able to change the DPI.
How would I go about doing that? I already tried to use Image.drawStringAtPoint, rendering single images to a QtWindow. Somehow, drawStringAtPoint doesn’t seem to work, I get this error:

ERROR: Primitive '_QImage_NewEmpty' failed.
Wrong type.
Instance of Image {    (0x11ba683f8, gc=34, fmt=00, flg=00, set=03)
  instance variables [5]
    dataptr : nil
    finalizer : nil
    name : nil
    url : nil
    scalesWhenResized : false
		arg this = <instance of PrimitiveFailedError>
		arg this = nil
		arg error = <instance of PrimitiveFailedError>
		arg this = <instance of Thread>
		arg error = <instance of PrimitiveFailedError>
		arg this = <instance of PrimitiveFailedError>
		arg this = <instance of Image>
		arg this = <instance of Meta_Image>
		arg multiple = <instance of Point>
		arg height = nil
		var ret = nil
	< closed FunctionDef >
		var width = 77.0
		var height = 13.0
		var tgHeight = nil
		var ratio = 0.16883116883117
		var str = "I Love Pixels"
		var font = <instance of Font>
		var color = <instance of Color>
		var strb = <instance of Rect>
		var targetWidth = 400
		var shadowColor = <instance of Color>
		var run = true
		arg this = <instance of Interpreter>
		var res = nil
		var func = <instance of Function>
		var code = "(
    var width, height, tgH..."
		var doc = nil
		var ideClass = <instance of Meta_ScIDE>
		arg this = <instance of Main>
^^ The preceding error dump is for ERROR: Primitive '_QImage_NewEmpty' failed.
Wrong type.
RECEIVER: an Image

trying to run the example from the Image.drawStringAtPoint help file.
I’m running SC 3.11.2 on macOS 10.14.6

Any help would be greatly appreciated! :~)

All the best,