I forgot to tell, I tried this already and it does not get grip too. But you're right. It's one tile in the puzzle.
I dug a whole level deeper and got it working in a more z3c-formish way than its done in plone.app.standardtiles:
SLIDER_IMAGE_FIELD_SPEC = getSpecification(ISliderImages["slider_images"])
<z3c:widgetTemplate
mode="display"
field=".sliderimages.SLIDER_IMAGE_FIELD_SPEC"
widget="plone.app.z3cform.interfaces.IRelatedItemsWidget"
layer="plone.app.tiles.interfaces.ITilesFormLayer"
template="sliderimages_tile_display.pt"
/>