yes and no. yes you can add it easily to your repository list and it works just like any repository. don't get distracted by the warnings, those are there for the people who don't bother to do any research.

just tell me then how you would deal with repos? please keep in mind that in order extras to be enabled by default, the contents has to be tested and controlled.

I know devs don't want to write stuff that makes ones device to freeze but one guy can never test an app such thorougly unless he/she has dozen devices wirh different apps etc installed....