Hi Rik,
I did a new custom change in the frontend section and now the page should load normally.
/components/com_publisher/views/issues/view.html.php is the page.
The problem is that I was thinking myself too for a way to select only some categories but is not quite simple. You can edit one article through Joomla and through Publisher in the same time and the edit is done on joomla content table, BUT the difference is in article status: Publisher add different statuses and here come the big sql when compare the article status under publisher and joomla.
Even I am not doing the sync in one page I must do it in another one and that pge will be slow one; I was thinking at doing a cron plugin but the sync must be done in real time right when you edit one article.
Anyway, I am investigating and I will try to find better solutions in future - for now the quickest solution were those custom modifications.