MigraDocXML not working correctly with PdfSharp/MigraDoc 6.1

It seems MigraDocXML is not compatible with version 6.1 of PdfSharp/MigraDoc at the moment. I updated my direct reference to v6.1 and many text-blocks rendered using MigraDocXML are strange, e.g. way too narrow and not page-width:

instead of this, when rendered with v1.50:

(same code, only different NuGet-packages)