There are so many places in 3dsmax which have an object input, or an array of objects as an input. Selection Sets, Light Includes/Excludes, Render Element properties etc.
It's about time these were all dynamic so you can plug a layer in as it will dynamically update as the layer content changes.
Input could be:
Object Names with Wildcards / Regex.
Layer Names with Wildcards / Regex.
Selection Sets with Wildcards / Regex
Filtering Rules to say get all objects with a certain material or a certain property.
XrefScene Entries
XrefObject Entries
Hierarchy Collections
User Property Tags
This would save a large amount of time when dealing with complex scenes.
