AFK players and Mahjong

Recently it has become a bigger occurrence that novice players join a game of Mahjong and then go AFK, not disconnected but AFK.

This means that each piece they draw, wait 15 sec; If someone discards a tile they can Pon or Chi, wait 15 sec; at the end of each round, wait 30 sec, making the game unbearable for those of us that enjoy it and bless your soul if you are matched up with two AFK players

I believe certain people do this because of 5.000 MGP reward of the challenge log, so maybe Mahjong should be removed from the challenge log or perhaps add an auto-afk timer like PvP or Eureka?

I believe Mahjong has an AFK kick timer, but it's... quite long.