@Patch concat filter is not yet fully supported. The reason is that I need to make sure whatever collection you end up after filters is still something you can convert into hyperlink. This hasn’t been implemented yet - that’s why concat filter will break hyperlink.
It would certainly be useful to support so you can emulate OR filters by simply creating individual collections and then concat them. I think or_filters would be ugly. Your example with Set1, Set2, Set3 is more elegant.
@Davide I just tested inventory kits and it worked:
{% for e in inventoryKits %}
{{ e.Name }}<br />
{% endfor %}
There was a bug with inventory items which I have fixed now.