hopefully a simple question to ask, not sure about the answer...
Given the MWEs
\documentclass{report}
\usepackage{amsmath}
\usepackage{lipsum}
\newcommand\BrText[2]{%
\par\smallskip
\noindent\makebox[\textwidth][r]{$\text{#1}\left\{
\begin{minipage}{\textwidth}
#2
\end{minipage}
\right.\nulldelimiterspace=0pt$}\par\smallskip
}
\begin{document}
\lipsum[1]
\BrText{Some text}{\lipsum[1]}
\lipsum[1]
\end{document}
in Brace and text in side margin, with particular attention to Medina's answer only because it seems to be the most foundational, i.e., without extra packages, I was hoping someone could extend this solution so that braces and margin text could cross pages.
A small caveat would be to also have the margin text wrap but I think I have that figured out with this:
\def\rightwidewidth{\dimexpr\marginparsep+\marginparwidth}
\newcommand\BrText[2]{%
\par\smallskip
% \noindent\makebox[\textwidth][r]{$\text{#1}\left\{
\noindent\makebox[\textwidth][r]{$\begin{minipage}{\rightwidewidth}#1\end{minipage}\left\{%0.1\textwidth
\begin{minipage}{\textwidth}
#2
\end{minipage}
\right.\nulldelimiterspace=0pt$}\par\smallskip
}
Though I was told this was not great - on my even pages it is right up against the edge of the page, odd pages are fine - maybe someone could help improve it?
For what its worth, I typically use amsart document class and lualatex engine...
addendum
After looking around more, e.g., Adding a large brace next to a body of text, Vertical line next to a block, across page breaks, and create a framed environment for a margin note, I've realized that any method would be spectacular for me - regardless of the need for new packages. Thanks!