Ultra low FX ! Half resolution and/or retro mode.
Or just DQ beta like graphics. Low fx is nostalgic but I think the DQ beta looks like lower FX than the current low fx with shadows disabled.
I actually managed to play DQ at 144p mode and it's interesting. Not playable on my phone S6 since I can't see the letters but small devices it's possible. 240p, 360p and 480p mode also. 720p and 1080p and 1440p. Seems all playable.
But I used Game Tuner Samsung app.
But having an option to halve resolution or more in the game without external application could be nice . Ultra low fx aka half resolution or more , no shadows , enemies be not so intensive even in packsize , etc.
Also because reducing lag as much as possible is good for hardcore farming even in low end device. Maybe battery saving mode?
Whatever it takes to satisfy others.