SEP Package questions about Auto-Upgrade

Scenario.

I upgraded my SEPM version from 11 RU 7 to 12.1 RU3. We are now on the process of upgrading the clients (which are currently running on either version SEP 11 RU6 or SEP 11 RU7).

We will be using Auto upgrade in SEPM Clients page. Adding Client Install Package > General > Client Settings, there's this option Maintain existing client features when updating.

Since are current version is 11. What will happen if we check this option? Let's say we have existing AV&AS plus PTP installed. Will it keep AV and AS SEP 11 features without adding the latest features of SEP 12 such as Download protection or it will be added? Will it still add the SONAR protection features of SEP 12 for PTP?

thanks