Yes, it can. For customers on the Prime plan, which includes free access to PAdES, it is possible to configure PAdES to be enabled by default at the group level.
(SignTime is designed to flexibly support documents that do not require PAdES—such as application forms or order forms—by allowing PAdES to be turned on or off on a per-document basis.)
*This feature is available to customers on the Prime plan or higher.
*This setting can only be configured by the group owner.
How to configure
From “Team” → “Settings” → “Document Settings”, enable “Automatically add PAdES.”