Yes! While it is not possible to attach a second seat to these strollers, you can use the Lascal range of buggy boards which enable a child to stand behind the stroller.
This includes the Lascal Mini, Lascal Maxi and Lascal Maxi Plus.
When using the Maxi Plus board with the saddle is on, there will be limits to what configurations it will fit with.
The Lascal Maxi Buggy Board is available for purchase here - https://www.winkalotts.co.nz/lascal-buggy-board-maxi/