How to measure programming language succinctness?
The ideas the question expresses are interesting but maybe insufficiently
fleshed out.  I can see a couple of points that deserve further
refinement.


It is difficult to "code the exact same functionality". In part that
is because what counts as "the exact same functionality" depends on
the chosen notion of program equivalence. For terminating programs
in sequential programming languages there's a canonical definition,
but when you move to concurrent, non-terminating programs,
canonicity vanishes, and you are left with multiple, reasonable
choices that are mutually incompatible. Secondly, but related to the
first point, different programming languages are fundamentally
different: things you can do in a low-level language can often not
be done in a high-level language. A typical example is to do with
speed.  Certain tasks can be solved intrinsically faster in assembly language
than in e.g. Prolog or Javascript (assuming conventional
compilation).
The KQuotient is subjective, in the sense that for any
given task, programmers A and B will likely have different length
base and test language implementations.
Moreover, the KQuotient is also task dependent, meaning that, given
a pair of languages, the KQuotient for Task A will in general be
different from the KQuotient of Task B.


Finally, even though I find the idea of measuring maintainability via
query numbers to reach consensus intriguing, I suggest to be more
clear about what kind of queries are relevant here (syntax?
semantics?), and how the concept of programmer consensus can be made
precise.