I made a post on these here, and this is u/MichaelMcRooney ‘s response.
K. Gonna have a chat. The mobile version doesn't have multiple lines because it negatively affects performance. We're looking into ways to give more options to optionally add more lines in the future for people with more powerful devices or people willing to take the performance hit, but other things are higher priority atm. :/
But I hope we can finally get it, or be able to turn it on/off.
Hola. Actually have an updoot on this. Most of the performance issues with the widget were worked out over a bunch of changes over time. Making the killfeed optionally support more lines is something that's on the todo list now, but eta is dependent on how priorities shake out. I can't say anything other than soonish. :/