begin{align}
    T(x) &= ae^{-frac{(x-b)^2}{2c^2}} \
    frac{1}{2} < a &leq 1 label{eq:m1va} \
    b &= SI{25}{degreeCelsius} label{eq:m1vb} \
    c &= frac{5}{sqrt{2 ln{2a}}} > 0 label{eq:m1vc}
end{align}
aligneqs{Model 1: Condition 1}{eq:m1va}
aligneqs{Model 1: Condition 2}{eq:m1vb}
aligneqs{Model 1: Condition 3}{eq:m1vc}

usepackage{tocloft}
newcommand{loename}{List of equations}
newlistof{equations}{equ}{loename}
newcommand{aligneqs}[2]% <=== HERE
    {addcontentsline{equ}{equations}{protectnumberline{ref{#2}}#1}}

InsertEquation{T(x) &= ae^{-frac{(x-b)^2}{2c^2}}}{Model 1: Base formula}{eq:m1gauss}
InsertEquation{frac{1}{2} < a &leq 1}{Model 1: Condition 1}{eq:m1va}
InsertEquation{b &= SI{25}{degreeCelsius}}{Model 1: Condition 2}{eq:m1vb}
InsertEquation{c &= frac{5}{sqrt{2 ln{2a}}} > 0}{Model 1: Condition 3}{eq:m1vc}
GenerateAlign

documentclass{article}
usepackage{xparse}
usepackage{etoolbox}
usepackage{amsmath}
usepackage{tocloft}

usepackage{blindtext}

% Add a new list for equations
newcommand{loename}{List of equations}
newlistof{equations}{equ}{loename}
newcommand{aligneqs}[2]%
    {addcontentsline{equ}{equations}{protectnumberline{ref{#2}}#1}}
setlength{cftequationsnumwidth}{2.5em}

% https://tex.stackexchange.com/q/451/53787
% https://tex.stackexchange.com/q/16883/53787
makeatletter
    % Temporary lists: store equations, references, and deferred commands
    gdeflisteqs{}
    gdeflistrefs{}
    gdeflistdefers{}
    newcounter{DeferredCommands}

    % Converts a number to Roman notation
    % https://tex.stackexchange.com/q/9718/53787
    % https://tex.stackexchange.com/q/23487/53787
    newcommand*{rom}[1]{expandafter@slowromancapromannumeral #1@}

    % Add an element to a list
    defaddtolist#1#2{%
        g@addto@macro{#1}{#2,}
    }

    % Add an element to a list, expanding it first
    % https://tex.stackexchange.com/q/67367/53787
    defaddexpandedtolist#1#2{%
        edefATL@temp{noexpandg@addto@macronoexpand#1{noexpand#2,}}
        ATL@temp
    }

    % Defers the execution of a command, storing it in a list
    DeclareDocumentCommand{DeferCommand}{mm}{%
        stepcounter{DeferredCommands}
        expandafterdefcsname DC@rom{arabic{DeferredCommands}}endcsname{#2}
        addexpandedtolist{#1}{DC@rom{arabic{DeferredCommands}}}
    }

    % Inserts an equation, its reference, and its TOC line to their
    % respective lists
    DeclareDocumentCommand{InsertEquation}{mmm}{%
        addtolist{listeqs}{#1}
        addtolist{listrefs}{#3}
        DeferCommand{listdefers}{aligneqs{#2}{#3}}
    }

    % Execute all the deferred commands of the given list
    % https://tex.stackexchange.com/q/28787/53787
    DeclareDocumentCommand{DeferredExecute}{m}{%
        @for i:=#1 do{@nameuse{i}}
        setcounter{DeferredCommands}{0}
        let#1@empty
    }

    % http://handyfloss.net/2007.08/latex-programming-how-to-implement-conditionals/
    newcounter{GArepnum}
    newififGA@first

    % Put all the equations inside a macro (first traversal) along
    % with placeholders for labels, substitute the placeholders with
    % their respective labels (second traversal), and show everything
    % inside an "align". After it, execute all the deferred commands
    % (stored when inserting an equation) that add the corresponding
    % lines to the list of equations.
    DeclareDocumentCommand{GenerateAlign}{}{%
        defGA@ans{}

        setcounter{GArepnum}{1}
        GA@firsttrue

        @for i:=listeqs do{%
            % https://tex.stackexchange.com/q/53068/53787
            ifxiemptyelse
                ifGA@first
                    GA@firstfalse
                else
                    % https://tex.stackexchange.com/q/74707/53787
                    edefGA@temp{noexpandg@addto@macronoexpandGA@ans{noexpand\}}
                    GA@temp
                fi

                edefGA@temp{noexpandg@addto@macronoexpandGA@ans{i ???}}
                GA@temp
                stepcounter{GArepnum}
            fi
        }

        @for j:=listrefs do{%
            ifxjemptyelse
                % https://tex.stackexchange.com/q/104506/53787
                begingroupedefGA@perform{endgroup
                    noexpandpatchcmd
                    {noexpandGA@ans}%
                    {noexpand ???}%
                    {noexpandlabel{unexpandedexpandafter{j}}}%
                    {}%
                    {}%
                }%
                GA@perform
            fi
        }

        begin{align}
            GA@ans
        end{align}
        DeferredExecute{listdefers}

        letlisteqs@empty
        letlistrefs@empty
    }
makeatother

begin{document}
    listofequations
    clearpage

    section*{Important formulas}

    blindtext

    InsertEquation{a^2 + b^2 &= c^2}{Pythagorean theorem}{eq:first}
    Following is eq.~ref{eq:first}, depicting Pythagora's theorem:
    GenerateAlign

    Blindtext

    InsertEquation{e &= mc^2}{Einstein Relativity theory}{eq:second}
    Following is eq.~ref{eq:second}, depicting Einstein's relativity theory:
    GenerateAlign

    blindtext
end{document}