Broz: "Been using the T-7 for over two years now. It is an awesome press and produces the truest ammo I have ever loaded, when used with the Redding Bushing dies. I have my total indicated runout down to .0005" average."
A/C, not to challenge your position but the engineers of all presses, including the T-7 and other turrets, have taken the slack in their designs into consideration, that's a given. But they cannot match the rigidity or precise ram alignment of any modern made single stage press.
Press rigidity and ram alignment isn't mandatory for quality ammo but surely no one would deny it makes things easier! What Broz and SHRTSHTR have told us is they are excellant loaders. They clearly know what they're doing but it isn't any magic from the T-7 that provides the terrific loaded round runout. I'm certain they could do it on any press made by using their dies, components and methods! So, yeah, a skilled handloader can make precise ammo on turret presses but it won't be as simple as on a single stage.
To see how much a turret head moves under the full pressure of FL sizIng and seating just put a precision dial indicator on them, it won't be difficult to measure.