The mod "Display Signatures Only Once per Page" no longer works under SMF 2.1.x, and has not been updated since 2009. I would be grateful if someone could update this extension, and would consider paying for it if it presents a good example of how to write a SMF extension.
Version: 2.1.4
Description: Save page space and bandwidth by only displaying each user's signature once per topic page.
Permissions: As I recall, this extension required no special permissions.
Features: It would be nice if individual users could enable/disable this extension, but this is not a requirement.
To save time for everyone,
@von Corax did ask for this in the mod's support topic but got no response.