I would prefer they bring back Kaiten, they could even reduce SAMs dmg further.

No seriously. The devs evidently didnt understand what Kaiten means for gameplay of Samurai. As of now, absolutely no Kenki managment is needed anymore: if you get Kenki, just empty your bar by spamming Shinten. There is no longer planing for your burst phase, no longer the good feeling you had when you managed to press the right buttons in a short period of time. A great part of challenge the job gave you is now gone and only boring spamming remains. Instead of pressing the right button at the right time you just press Shinten when you can, which barely reduces your APM overall. Also, what defined the SAM where the high dmg number from Midare/OgiNamikiri/Kaeshi which were only possible with Kaiten.

But as i said at the beginning, its not about the dmg. Kaiten was one, if not THE core abillity of the Samurai and by removing it, they actually managed to give the SAM player a worse gameplay experience. Even if the DMG numbers may go up in the future, the lack in gameplay will remain, until Kaiten is brought back.