New
#11
It's not a checkbox, it's a button, but if you activated from a legitimate Windows 7 or 8.x, then yes. You can click the "stop insider builds" button and it will stay activated and not expire.
However, if you wait until the next set of Insider builds go out, you will no longer be in that situation, because insider builds will be beta builds that have hardcoded expiration dates. If you wait until after the new builds start, then you will have to re-install the RTM release if you decide to stop insider builds.