@jonatandor35 Yes the perfomance derives from too many query calls. On a dynamic page I use that for a dataset and use the filter to get directly the “referenced items”. It’s much more faster then Query it.
But anyway, have a look at my Projekt with Multi-Query calls. Because when you open the Filter (click the Button “Filtre”), you see all the Checkboxes and that are all “Multi-Item References” to one Collection. And while you clicking the Checkboxes everytime its fire a Query and so fahr it works smooth. I hope that stays so when there are over 100 Objects. 
The Page: https://noe342.wixsite.com/website/kopie-von-activites