If you use the newest version of Neos you could write:
properties = Neos.Fusion:Map {
items = ${myItems}
itemRenderer = ${q(item).property('myProperty')}
@process.removeDuplicates = ${Array.unique(value)}
}
Another small hint: q(item).property('myProperty')
is much faster than item.properties.myProperty
, as it only loads one and not all properties