How to change default page size when exporting to powerpoint?

Hi,
I have created a fixed size report with size Din A4.

Exporting to PDF works as intended but when I export to Powerpoint the exported slides have Powerpoint standard 16:9 format => blank space on left and right side.
Unfortunately, those slides have to be used in a presentation with size Din A4. That is why the straightforward solution to change SAC format to 16:9 does not help in this case.

I already created a new default design in powerpoint with size Din A4. However, when SAC exports to ppt the end result is the same 16:9.

Export to PDF and import to PPT is possible, but end users will not be satisfied.

Any suggestions?

Best regards
Edgar