Errors and Questions when using notifySigner method / email.notify template

Hello! Thank you for reading my post. My understanding is that the notification email (email.notify) is the only email template that can be triggered programatically from the eSignLive system. I had a few questions on this functionality: Question 1. When I am in the sender UI and click on the "Notify this Signer" button, it will successfully send an email to the signer using the email.notify template and include the "Email message" that I have entered in the Advanced Options in the package settings. However, I am trying to trigger the email.notify emails programatically using the Java SDK in order to tailor specific messages to specific signers. I am using this code in order to send the notification: eslClient.getPackageService().notifySigner( packageId, "[email protected]", "HELLO SIGNER" ); When using an email that is already on the package, I get the following error message: "error.validation.userAddition.duplicateEmailUsage". When using an email that is not already on the package, I get the following error message: "error.notFound.signerNotFound". I guess my question ultimately is, what emails will notifySigner accept (in order to not get the aforementioned error messages)? And, what variable ($PACKAGE_MESSAGE?) in the email template will the third parameter ("HELLO SIGNER" in the example) eventually show up as in the email.notify template? Again my goal is to tailor the message differently to different signers. Question 2. Are there any restrictions on the package status regarding when I should be able to use the notifySigner method? I tried using the notifySigner and received the previous error messages when the package was both in the DRAFT and SENT statuses. Question 3. I didn't see anything like this in the documentation, but I was wondering if we also would have the ability to change the text of the email.notify email subject based on who we are sending the notification email to? Thank you so much for your time and guidance! Garrett