Correct way to pass options to (class) loaded packages

Question

I write a document with the book class and have a file (mainstyle.sty) with a number of packages that I use (pdfx, lipsum, placeins, etc\ldots).

I recently started playing around with tufte-book and got several warnings, errors and unpleasant messages. Got my hands on it, but I realise that it will take time to tune it little by little. I would like to switch classes easily and load the corresponding packages and options easily.

The main issue here is that the class tufte-book loads several packages previously, and thus my file crashes if I just change the class on the fly.

Right now, what I have in master.tex is:

%\documentclass[a4paper]{tuftebook}
\documentclass[12pt,a4paper]{book}
\usepackage{./inc/mainstyle}

\begin{document}
    text text text
\end{document}

My idea now is to split mainstyle.sty in two files and use a mixture of conditionals and \PassOptionsToPackage (inspired by these two questions). The idea would be to have a parameters.sty file and a load.sty file, with the main document modified like:

\input{./inc/parameters}
%\documentclass[a4paper]{tuftebook}
\documentclass[12pt,a4paper]{book}
\input{./inc/load}

\begin{document}
    text text text
\end{document}

Then I'd have something like:

%parameters.tex ---------
\PassOptionsToPackage{pdftex,pdfa,hidelinks}

and:

%% load.tex ------------
\makeatletter

\@ifclassloaded{book}{
    \usepackage{hyperref}
}{
    \@ifclassloaded{tufte-book}{
        % hyperref was already loaded
    }
}

\makeatother

This is roughly the same that is proposed in this other question, right?

However, it feels cumbersome and I don't know if I'm just messing things around. Also, my understanding of conditionals/macros and such is still very limited.

Is this the right way to go?