@Marcelo77 

The short answer is that most of the features that are disabled in AP mode require the device in router mode to work.   When you switch out of router mode, you are telling Deco to allow the other devices (ISP Router for example) to do the main router functions.    

For example the Parental controls - in Router mode the main deco (central node) filters the traffic coming and going from the web as everything has to go via it to the internet, therefore you can apply parental controls on that one connection.  In AP mode, the same Deco node is just one of x number of Deco devices and therefore there is no central point to control the traffic to the WAN, as this is now done by your ISP router it wont take orders from the Deco.

The only way to do this is in Router mode, from a technical point of view, it makes perfect sense