Choose preview mode of child layer features inside relation widget within parent feature form

Currently (Input v2.2.0) if there is a relation between child and parent layer and the relation widget is present in parent layer form to show all child features added, it can be shown in two modes - a field containing data from some of the child feature fields or a photo/gallery preview if one of the fields in child form is set to attachment widget. See picture below for both of these previews.

The idea is to choose between these modes because sometimes even with attachment present in the child feature form it would be more convenient to have it shown just as the fields data preview, not gallery.