Since PDF-AS cl 3.3 is not available for download, this issue was found in the most recent available version (PDF-AS cl 3.2)!
According to page 16 of the enclosed documentation "PDF-AS-3.2-Anwendungsbeschreibung.pdf" the default value for the pos option is:
-pos x:auto;y:auto;w:auto;p:auto;f:0
Therefore the following two commands should be equivalent:
pdf-as.bat -mode sign -sigmode textual -connector bku -pos x:auto;y:auto;w:auto;p:auto;f:0 test.pdf
pdf-as.bat -mode sign -sigmode textual -connector bku test.pdf
Nevertheless the result is different with the enclosed test.pdf: whereas the first alternative applies the signature block on the last existing page, the second alternative appends an empty page with the signature block only.
Is there a workaround available for placing the signature block on a particular page (p-subparameter) with the default behavior of placing it on the free area on this page?