Hi Stefano,
Thanks for contacting Syncfusion support.
In ReportPlatform SDK samples, we have provided the ASP.NET Core sample support to load the RDL only from Reportserver. We have completed the ASP.NET Core support for ReportViewer to load the local RDL file. It is planned to include in our Essential studio 2018 volume 1 main release, which is tentatively scheduled to be released in the month of February.
Regards,
Yuvaraj D.