I like the idea of having multiple states for a rack.

Especially when trying different module positions within a rack.
I do a lot of copies just to re-shuffle some modules. Having several states would be great in this context.
I suppose this should be easier to implement as the initial request to have different modules for the same rack.
What i ask for relates to the same set of modules, just different "coordinates" for them in the rack.

EDIT: I just realise this may have a bad impact on selling Unicorn accounts, because users do not need multiple racks to try out variations anymore. Just make it Unicorn only :) Another good reason to go "pro" hehe

A Eurocrack Pusher: "The first time is for free" ;)