I have proved the following negative result:
Theorem $latex \mathsf{pFCD} (\mathfrak{A};\mathfrak{A})$ is not boolean if $latex \mathfrak{A}$ is a non-atomic boolean lattice.
The theorem is presented in this file.
$latex \mathsf{pFCD}(\mathfrak{A};\mathfrak{B})$ denotes the set of pointfree funcoids from a poset $latex \mathfrak{A}$ to a poset $latex \mathfrak{B}$ (see my free ebook).
The theorem and its proof were modeled after theorem 3.8 in this article (December 1979) by Zahava Shmuely.
It would be probably interesting to a find a common generalization of my theorem and the original Zahava Shmuely’s one.