Its my understanding that if the laser is directed to go negative of its origin I will get a “soft error” and the burn will terminate. Is there a way of stopping that error or overriding it?
No, because that mean the laser head would travel through the frame of the machine …
You’re probably thinking of GRBL’s Soft Limits setting telling the controller to verify every motion will end within the travel limits before starting.
Assuming the machine has been properly homed, enabling Soft Limits prevents the controller from smashing the laser head into the sides of the machine, which is generally a Good Thing™.
Most machines do not have the additional switches required to enable Hard Limits, which can catch problems due to the motors losing steps while moving. This is generally more troublesome with “real” CNC machines carrying rotating spindles that can crash into vises.
The soft limit setting is probably what I am referring to. I understand why it is there. I am resetting the origin to the middle of the work area so in this case there is no danger of crashing into the frame of my machine. My laser has no homing switches so it can’t be homed. Is there a temporary way of overriding GRBL’s “Soft Limit Setting” ?
LightBurn requires a machine origin in one corner, not the middle, so that all coordinates have the same sign.
I like having the origin in the middle of the work area, too, but that’s not how LightBurn works.
Oh, yes, it can. 
With homing disabled, the controller sets the origin to wherever it is when it starts up. That origin must agree with LightBurn’s requirements, so you become part of the homing operation.
This section of the doc covers what you must do with regard to homing:
Basically, LightBurn is not a CNC machining program and does not operate according to the CNC assumptions you’re familiar with. Although it sends G-Code commands to the controller, the usual concepts don’t apply.
If you haven’t read through it, the whole section on CNC machines will explain more about what’s going on: