Bad news: The design would work only for the 1.83%
I asked the only lefty close friend I have to try out the current version of LeftScripts today. My design didn't work well for him at all because the design principles are in conflict with his preferred grip and hand placement. His style looked like how a professional e-sport FPS player would hold a high-sensitivity configured gaming mouse which is similar to the right version of this image. The current LeftScripts design is only fine-tuned for lateral tripod overwriting similar to the one on the left of the photo.
This unfortunately means the design will be useful to only a portion of left-handers. I looked into different common grips and their inferred distributions. It seems only ~18.3% of lefties are my target group which from global population POV. It's just ~1.83%
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