No, that is not what Ike meant… please see this: https://simple-press.com/documentation/codex/api/template-functions-and-the-api/display-template-functions/topic-view/sp_postindexusersignature/
the signature height is controlled from the template file… so assuming you mean the signatures at the bottom of each post, that would be in spTopicView.php template file… this line from unified:
sp_PostIndexUserSignature(‘tagClass=spPostUserSignature spCenter&maxHeightBottom=55’);
try adjusting the 55 height of the signature… there is a similar one for mobile in the same file…
We have a new theme coming out soon (Reboot) that makes heavy use of CSS3 and flexbox to get rid of the need for the signature height… when the current themes were written browser support for those was not that good… but now, they are and we can switch too it…