Short answer: you can’t.
When you start a job from LB it generates the entire path data (such as gcode or whatever your controller uses) and caches it in memory and then streams it to your laser. If you high pause all it does is pause that stream. Unpausing just starts it up again and does not regenerate the cut/engrave path data.
We don’t currently have any plans for that sort of feature exactly, though we have discussed allowing you to restart a job at a specific point in the cut/engrave path. So you could effectively do what you want. The process would just be stop instead of pause, then change settings, then restart while selecting where to start.
I recommend adding a feature request by following these directions: Voting System for New Feature Requests - Fider
It does help us prioritize work on new features.