I’ve proved:
$latex \bigsqcap \langle \mathcal{A} \times^{\mathsf{RLD}} \rangle T =
\mathcal{A} \times^{\mathsf{RLD}} \bigsqcap T$ if $latex \mathcal{A}$ is a filter and $latex T$ is a set of filters with common base.
$latex \bigsqcup \left\{ \mathcal{A} \times^{\mathsf{RLD}} \mathcal{B}
\hspace{1em} | \hspace{1em} \mathcal{B} \in T \right\} \neq \mathcal{A}
\times^{\mathsf{RLD}} \bigsqcup T$ for some filter $latex T$ and set of filters $latex T$ (with a common base).
See preprint of my book.