Hi,This was a topic we did a lot of consideration on. The game has timeout protection in only two places, during patching and during matchmaking. These two screens met the criteria of (a) it is a non-interactive event and (b) it comes to an end after a set time all on it's own.
During a game (b) is not a guarantee. Vs AI games are not timed at all. In PvP, maybe your opponent is doing some Cloud Drinker combo shenanigans. We didn't want to leave your phone vulnerable to battery drain or to security issues because you set it down in the middle of a Vs AI game and forgot about it. In general, LoR's round structure also makes it very interactive, and for those time where your opponent may be thinking, we instead focused on giving you more interactive things to do, like petting your Guardian or sending your favorite emote for that situation. (Are you a Heimer, Quinn or Gangplank? Quinn is my favorite.)
Hope understanding our philosophy on this gives you some context about this issue.
Thanks for playing!