When you pass a boolean to some attributes (e.g. autoSave, autoCorrect) in 15, they don't work correctly because they actually want a specific string (yes and no). I think there were also some attributes that want on and off.

Let's just “make them work”? Could use a special flag/whitelist for that. There should be very few of these.

Similarly we should probably make <script crossOrigin /> be valid and turn into <script crossOrigin="anonymous" />. Currently I don’t think this works on master.