I did small research and tried to count number of tiles Saki need to change for all yakumans:
Code:
Kokushi Musou (13 Orphans) .............. 7 tiles
Chuuren Poutou (The Nine Gates) ......... 9 tiles
Suu An Kou (Four concealed triplets) .... 6 tiles
Dai San Gen (Big three dragons) ......... 8 tiles
Shou-suushi (Four Little Winds) ......... 9 tiles
Dai-suushi (Four Big Winds) ............. Not possible
Ryuu-iisou (All Green) .................. 11 tiles
Suu Kantsu (Four Kans) .................. 7 tiles (not usable imho)
Tsu-iisou (All honors) .................. 10 tiles
Chinroutou (All Terminals) .............. 10 tiles
So only Kokushi Musou and Suu An Kou are available at this moment for Saki to win and if I consider Koromo is already Tenpai I don't think there will be another go around.