Finally got to fix up the file and publish the Slider Prototype Variations on Figma Community. Hopefully this helps someone in the future when they’re trying to figure out how to make smoother swipe-to-action prototypes on #Figma. 
https://www.figma.com/community/file/1277562905887280569/Slider-Prototype-Variations
FigmaSlider Prototype Variations | Figma CommunityFigma Community file - If ever you need a sample swipe-to-action slider for your prototypes, sharing the two things that worked well for my use case, interactions-wise. The feel of the prototype is smooth enough.
Explanations
First version is just via Smart Animate, where you let Figma do the animation feel for you. T...