What is the feature?
Right now, getValues is a method on which the records parameter is TRow<S, N>[].
It’s pretty fine (autocompletion yay!), but misleading: the contents of the records are actually partial records as defined in the dependencies property.
records’ type should ideally depend on the dependencies array.
Similarly, the return type of getValues is Promise<unknown[]> | unknown[]. Ideally, this should be set by the columnType property.
What problem does this solve for you?
This clears up a discrepancy between types expression and actual runtime values.
As properties which are not listed in dependencies do not appear in the records content whatsoever, accessing them can cause crashes or other undesirable behaviours.
I’m… not sure what can go wrong if the wrong type is returned from the function (an array for a Number type for example). I don’t want to know 
Who else would be using this feature?
Anyone adding smart fields with a type-aware code editor on the Node agent.