After using a 'Start/Stop Smooth Zoom/Scroll' action, the scrollbar remains visible. The scrollbar disappears properly after manually scrolling.
Workaround: use a 1px 'Send Scroll Event' directly after the smooth actions
BetterTouchTool version: 6.683
MacBook Pro M4 Pro, macOS 27.0 Beta (26A5388g)
P.S.: amazing piece of software!