答案1
我很同情你。
\documentclass{article}
\usepackage{amsmath}
\makeatletter
\renewcommand{\make@df@tag@@@}[2][]{%
\gdef\df@tag{%
\tagform@{#2\rlap{\hphantom)#1}}%
\toks@\@xp{\p@equation{#2}}%
\edef\@currentlabel{\the\toks@}%
}%
}
\makeatother
\begin{document}
\begin{align*}
f(x) &= absuc \tag{First tag} \\
&= abshgi \tag[.]{Second tag}\label{X}
\end{align*}
\eqref{X}
\end{document}