>>529884665
You can fix a bad wait easier in sanma, but you don't have time for it; everyone else reaches tenpai too quickly.
Losing the initiative in sanma is a death sentence, as the your riichi declaration tile pretty much always deals in.
In yonma, many strategy guides will focus on how to push iishanten against riichi. But in sanma, pushing iishanten is almost always forbidden, and the real question is whether or not oikake riichi is worth it.
>>529884839
Why care so little about the more popular mode?

I used to always push my expensive hands against tenpai very late in the game, under the assumption that both me and my opponent have a 50% chance of victory, so I might as well fight.
But it's false, since I'm the one who has drawn musuji, and there's no guarantee my opponent is going to draw any risky tiles for the rest of the match. I'm already at a significant disadvantage, so it's often correct to fold.