I've noticed that the HtoA "Collection" operator Selection field is set and locked to "String" rather than say "Operator List" this means that artists can't drag& drop into the selection field?
The management of this "Collection" node is also lacking. A general use case would be use expressions to collect assets in the scene and do overrides with Set Parameter.
For example: If there are 1000+ assets in the scene, but 50 needed to be individually selected and added to a FG layer/pass this would be very un-intuitive for artists to control
ie. *rockA* *plantB_01* *plantB_02* *pebbleC* *plantD* 50+ times.
Likely the artist would at least want to select the assets in the viewport / scene and drag&drop into the selection field?
Either way, once it's there it would also be difficult to modify later. There should be a "list" view in which assets can be easily added and removed.
Maybe I'm missing an easier way to intuitively control "Collections" ?