I want to use
\textstyle as the default in my amsmath equations, while retaining
\displaystyle as unchanged command for compatibility across documents.
Apparently, amsmath hardcodes the use of
\displaystyle and thus in [ \textstyle as default method of displaying mathematics ] it was recommended to use
\let\displaystyle\textstyle to achieve this.
Is there any possibility to make
\textstyle the default, without redefining