I have been having an issue with the location of signatures /initials for a long time now. Because a picture is worth a 1000 words, Im going to provide a screenshot as well as a
In most cases, the yPosition aligns with the top edge of the tab. The top edge of the text tabs(For ex: DateSigned, FullName, Company, Title etc) seem to correctly align with the yPosition.
The signature tabs seems to have additional offset and it can differ based on the scaleValue used. See this answer for the offset values.
Tip:You can use the Docusign Console to tag documents and get the accurate X&Y positions using the getRecipients call. You can then specify those coordinates in your API request to create new envelopes. See this answer
GET /v2/accounts/{accountId}/envelopes/{envelopeId}/recipients?include_tabs=true