He said his output plummets to 10% at its lowest (which is when he's using his cursed technique), and notices his hand twitches when that happens. Meaning the suppression is maxed when he does that, and his hand twitches. The context is about Megumi's suppression of Sukuna, the output is only a part of it. By common sense, it's referring to bodily control.
Also, Megumi was ALWAYS suppressing his cursed energy output, just suppressing it hardest when Sukuna uses his technique. Cursed energy output matters when it comes to reinforcement, so he would already be weaker than 16F.
That wasn't Sukuna's strongest dismantle, he was underestimating Ryu and so it didn't kill him, in Sukuna's own words. It also wasn't cleave, it was just Sukuna not holding back the 2nd time and using dismantles. We can literally see the moment Ryu's head gets cut, Sukuna's not physically touching him, and it doesn't follow the cleave pattern. Gege is VERY consistent with his portrayals of cleave and dismantle, down even to the sound effects.
Maki is relative to Yuta when she already has the special senses, so this argument is null.