Two things to note here ...
1. JUSTIFY is not the solution. Note the second paragraph in the JUSTIFY section
http://4js.com/online_documentation/fjs-fgl-manual-html/#fgl-topics/c_fgl_FSFAttributes_JUSTIFY.html2. In the GDC, default position for IMAGE in table is center,
https://4js.com/support/issue/?id=GDC-4308. There is a task GBC-3800 to get the GBC behaviour to match GDC. Where there is a clear difference like this between 3.20 and 4.01 behaviour you should not be shy about reporting a case to support. The number of reporters is a factor for priority so even though there maybe a simple 3 line workaround via GBC customisation, you should still let us know you had to do that so that we give the issue the attention it deserves. (It's not a 3 line solution for us as we have to a) consider the alignment presentation style attribute and the fact that default for GRID is top left and for TABLE it is center! and b) FLIPPED rendering)
3. There is another interesting case we have on the books GBC-4249 that the introduction of STRETCH=X has highlighted, for non-text widgets such as CHECKBOX, RADIOGROUP how should they behave when the grid is stretched and getting consistency with what happens in a TABLE. I suspect the alignment presentation style attribute will be extended beyond IMAGE to other widgets