Works like a charm!
For future readers, use “Reverse Scroll Direction” instead of “Inverse scrolling …” from the settings.
Edit:
Since applications like Homerow and Keyboard Scroller run in the background, I suspect this scroll modifier doesn't affect them.
This is also explained in the modifier's documentation, which indicates that it only affects the frontmost application.
BTT has introduced many great features recently (I’ve been a long-time user), and I’m hoping we’ll see smooth scrolling and keyboard-based scrolling added in the future so everything can be integrated into one great app. I can submit a few feature requests like this one and this one just to have some of these features under the radar.