| 
 | 
whatever rocks your boat... 
If you feel curious, you could replace /etc/apt/sources.list  on dietpi with the one from your Lubuntu and check how ti goes. 
The DietPi experience/magic , as far as I can tell is done by scripts running under /DietPi and probably work fine with ubuntu repos. 
 
If you decide to try, please share your experience with us |   
 
 
 
 |