Change signer – make sms authentication as default

Hello, We have integrated our salesforce application with onespan using APEX SDK for our signature use cases. We have this below scenario, could you please check how can we handle this? 1. Email sent to signer named 'John Smith' for signature. On all our signature request packages, we have made SMS authentication as mandatory. 2. John Smith opens the email, uses ‘Change Signer’ button (see the screenshot named changesigner) to assign it to Tom Murphy. Now at this point user has to click on 'Authentication' tab to set any authentication category. What we want is, always default SMS as authentication category and it has to be required (we don’t even want to display the Email and Q&A option). Could you please suggest how can we chive this? 3. Also , for some customers we want to disable 'Change Signer' option, : Is it possible in apex SDK ,when we create a package and set up signers, can we set an option ,so that a particular signer doesn’t see ‘Change Signer’ option at all? Thanks Anway Kabir