Placing points on right without margin

Question

I'm using the exam document class, and have played around with the options for points placement. Essentially, I want something that works like \pointsdroppedatright. The only problem is that it creates a margin. I was hoping to avoid the margin altogether, such that the text appears much in the same way using \hfill would push it rightwards. I believe this can be done with qformat, but I don't know how to do it for parts, subparts, etc.

Here's a minimum working example of what I have now:

\documentclass{exam}
\pointsdroppedatright
\marksnotpoints
\begin{document}
    \begin{questions}
        \question Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
        \begin{parts}
            \part[4] Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. \droppoints
        \end{parts}
    \end{questions}
\end{document}

Here's what I want:

Answer 1

A simple solution:

\documentclass{exam}
\usepackage{xpatch}
\pointsdroppedatright
\marksnotpoints
\makeatletter
\def\mydroppoints{%
  \leavevmode\unskip\nobreak\hfill
  (@points~marks)
  \par
}
% show marks automatically
% \xpretocmd{\endparts}{\mydroppoints}{}{}
\makeatother
\begin{document}
    \begin{questions}
        \question Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
        \begin{parts}
            \part[4] Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. \mydroppoints
        \end{parts}
    \end{questions}
\end{document}

EDIT

According to @David Purton, there is a better solution which allow line break if there is not enough space.

\def\mydroppoints{%
  {\unskip\nobreak\hfil\penalty50
   \hskip2em\hbox{}\nobreak\hfil(\@points~marks)
      \parfillskip=0pt \finalhyphendemerits=0 \par}}

Response to the comment

When point is 1, show 1 mark rather than 1 marks.

\def\mydroppoints{%
  {\unskip\nobreak\hfil\penalty50
    \hskip2em\hbox{}\nobreak\hfil
    (\@points~mark\expandafter\ifx\@points1\else s\fi)
    \parfillskip=0pt \finalhyphendemerits=0 \par}
}