Steps to reproduce the issue

Create or install a module that has a subform
In the subform.xml add field layout utility classes (parentclass) to a subform field https://issues.joomla.org/tracker/joomla-cms/32422
Open the module through Joomla admin panel
Navigate to the module's subform field

Expected result

parentclass markup is applied to xml fields within the subform

Actual result

The only parentclass markup that appears to work is "stack"
All all other markup ("span-1", "span-1-inline" etc) is ignored

System information (as much as possible)

Joomla 4.1.0

Additional comments

In the module admin display, subforms are shifted to the left to accommodate the drag-and-drop "handle" used for reordering items
This shift to the left reducing the amount of horizontal screen space for subform fields.
Being able to use "span-inline" can save space vertically within each subform item by allowing more than one field in a row.
This is useful when re-ordering subform items:
The shorter the subform item is (in height) the easier it is to drag-and-drop among a list of other subform items