Orgmode exported to latex automatically renders lists into enumerate blocks. The trick was to insert some parameters WITHIN that enumerate block to tweak a particular list output. The answer¹ turned out to lie in the #+ATTR_LATEX: command, as follows:

Orgmode In

#+ATTR_LATEX: :options \setlength{\itemsep}{1pt} \setlength{\parskip}{0pt} \setlength{\parsep}{0pt}
1. first
2. second
3. third

Latex Out

\begin{enumerate}
  \setlength{\itemsep}{1pt}
  \setlength{\parskip}{0pt}
  \setlength{\parsep}{0pt}
\item first
\item second
\item third
\end{enumerate}

Footnotes

¹ StackExchange for this question, including the answer from NickD: https://emacs.stackexchange.com/questions/64234/how-to-include-instructions-within-the-enumerate-in-orgmode-latex-export