I'd like to see a feature added to enable/allow maps with multiple copies of a layer to be downloaded and used offline in Collector. If needed, the copies that are created would be required to have editing disabled, or Collector could force editing to be disabled on any copies created, upon download. If editing is needed, the original layer would need to be turned on and edits made to features in that layer, but copied layers could still be used with different filters and symbology set as needed and overlaid on top of the original layer.
This idea stems from the limitation in the New Collector app that does not allow a map to be downloaded for offline use when multiple copies of a layer are present within the map. The only current solution is to have the layer owner create multiple view layers, which can then be added to a map and used offline in Collector. This can become a cumbersome task for the owner of a feature layer or view layer that is shared and used by many other users at the creator license level.
Here are a couple of other discussions about this:
And another idea that would solve this problem: