I'm not sure what adding an indexed version would gain, it's drops the event count on example projects that allow you to switch between noise types, but in real usage I'm not sure why you would want behaviour like that?
To make it easier to compost the different noises together.
Like the first part of a loop gets the z of one noise, the next another.
If its too much to add I'm sure it would be easy enough to serialise it using Array instances.
Although that does bring up the idea of treating the noise as an array.
Giving it a for each, etc.