What's currently the best practice with launcher icons for J2ME applications, which can be installed on all Nokia's S40 and S60 devices with qvga or better? I guess several different jar files would need to be created for "native-looking" icons, is there any official documentation or recommendations on this?
There are guidelines for icon sizes and styles for full touch and touch and type S40 devices :
Bitmap size 56x56 pixels, rounded rectangle background 50x50, white logo 30x30
Touch and type:
Bitmap size 43x43 pixels, rounded rectangle background 37x37, white logo with drop shadow 26x26
For non-touch, the recommendation is to use same icons as touch and type . However, other resources such as  say, that the correct icon size for S40 qvga devices would be 46x48. How do touch and type icons work in practice on older devices? If scaling occurs, the rounded backgrounds of icons will probably look quite bad and also the backgrounds may look really small compared to icons where the picture fills the whole area. The touch and type style 43x43 icon looks unsymmetrical and too small compared to others at least on N81, which is qvga S60 3rd FP1 device, I don't have older S40 devices at hand to test.
From the above, at least 3 different jar files would be needed:
1) Full touch style
2) Touch and type style (perhaps used also for newer non-touch devices)
3) Everything else - 46x48 bitmap icon (with rounded corners but the rounded area filling the whole bitmap), with a svg using S60 template for newer S60 devices, which support svg
Is there another way to do this? Or is it better to just forget about the icon guidelines also for newer devices, make a single jar, and use a 46x48 icon, with no rounded rect background, for all devices?