@Adám Yes, I see why. It would have been nice if ⎕VSET would always take exactly two things in the right arg, either single name and value, or a set of names and values, that way no need to enclose one, and multiple names could be vector or matrix. I think the use case for nested pairs is much less. But that then complicates ⎕VGET and its default value situation...

There are other considerations too. Sometimes you have some fixed names you want to set, including some that you want to set or not depending on a condition. ⎕VSET alwaysPairs,cond/sometimesPairs is nicer than ⎕VSET alwaysNames alwaysValues,¨cond/¨sometimesNames sometimesValues

And there will always be some tools that take name-value pairs (like many sysfns currently do) and for those we need to get such pairs, and by extension also set such pairs.

And yes, you can choose to supply default values for only a subset of the names in ⎕VGET but only if you use pairs.

Yes, noted. A lot going on.