The screw and plastic part is a stopper so you don't insert the seatpost too far.
I have both the 2025 manual dropper and the Transfer Neo. Love the Neo due to no routing any cables and instant response. The installation alone is worth a lot. Once installed, they function very similar with one difference - the Neo is on/off so it either releases or is locked. The manual one will go up slow or fast depending on how much you push the lever. In practice it doesn't really make a difference when riding.
Really to me it's a convenience thing. Or, if you are sharing a bike and need to always move the seatpost in the clamp, the wireless is easier than pushing/pulling the cable housing through the frame.
