Seems to be holding fine but I will probably end up going with a derivative of this remix (https://www.thingiverse.com/thing:1742253) since it clamps securely around the rail to relieve some anxiety about the mount shaking off and also allows angle adjustment.
That said, I will definitely keep this one in case a friend needs to borrow a light or I need to throw one on my mountain bike one day.
Thank you to the designer for sharing!
did not need to be 100% infill that was a mistake I forgot to change from a previous print. would probably do around 50 if printing again.