Hi Sinan,
Sorry for the late reply - Your report got lost among all the others.
The visual grid builder basically follows the same principle that is applied to manual grids. There it is also not possible, for example, to assign a grid-column or grid-row to the rich text element, although this is basically possible (e.g. via custom CSS).
If we make this possible at some point, it will also be possible in the grid builder.
Best regards,
timmse