if |set|+* (Toggle) is yes, then when i edit, i *am* editing the autosaved version.
An alert message appears just under the card header, (like requests about memorizing passwords in your web browser).
If the option is off and there's an autosaved version, a similar alert appears letting you know there is an autosaved version, and the link takes you to it (in the Changes tab).
yuck - efm (want to prevent proliferation of settings, though I do want to make it possible to do in modules. However, if someone really wanted this, the module could probably just turn it on (not give a setting to turn it on).
+discussed in support tickets+relevant user stories