also, no auto-suspend = no more easy-arena trick(or finding your opponent in the arena simply by wagering gold, and turning off power in the event your unit has a disadvantage(weapon triangle-wise)/you think your unit will die in the arena to the enemy, and turning power back on, and rejecting the wager, and reentering arena, wager, get a new enemy)..
^ because of that fact, the arenas of this game are a whole different ballgame than the arenas from fire emblem: blazing sword and sacred stones, where you can auto-suspend, while in this game, if you have to stop w/o losing chapter progress, you have only two options: manual suspend or save. If there's no way you can do either w/o losing an important character, you can start all over again(you can't directly restart chapter in this game, just like fe4-fe5 which, oddly, don't have a "restart chapter" command(that fact applies to this fire emblem game too because it shares that observation with those two games, meaning if you made a bad mistake, since the rng can't save you w/o auto-suspend, you have to make a new save file...), and play up to the point of where you made the mistake on your old file...
^ sure wish it still did it, but :(