slideClampOverhangViewports property
Padding past the viewport edge (in viewport-heights) used as the start position (slide-IN) or end position (slide-OUT edge ghost) for FLIP slides whose prior or current is off-screen. A small overhang gives the row visible motion into / out of the viewport rather than appearing/disappearing exactly at the edge.
Defaults to 0.1 (10% of viewport extent). Set to 0 to clamp exactly at the viewport edge; set higher to extend the start/end further off screen (lengthening the visible portion of the slide-in entrance).
Live setting; changes take effect on the next slide install.
Implementation
double slideClampOverhangViewports = 0.1;