SNAC client upgrade

Hello!

I would like to ask these questions:

1. If I upgrade my SNAC SEPM to 12.1 and I have my clients running on 11.6, can i set my client groups member clients to not automatically upgrade at once from the console/

2. If I have a setup with SNAC only, then I installed SEPM for SEP to have the SEP functionality from the server? Would the existing SNAC clients will be installed with SEP components or I will have to use an SEP package to remotely deploy to them?

Thanks