Not sure I follow what you are meaning. Do you have physical limits? If not then how do you reference your machine? The machine needs to be referenced so that you can take advantage of SoftLimits. The reason for this is you need to tell Mach where the "true" zero position is (G53 Zero position) You can then move away and zero on a position you want your work to start at and that will become your new working zero position (G54 )
Mach still knows trhe real zero position (G53) and with Softlimits correctly set will stop you from moving outwith this area. Your G54 zero position is not affected by your softlimits, what I mean by that is the softlimits do not change to the offset zero.
Hope you follow as I am not the best at explaining things but I will try and give an example, I will just use X and Y axis to make things simpler for me.
If you home your machine and it has a 1meter by 1 mete travel the G53 will be at the extreme end of each axis travel (your tool will be lower left corner). If you set up your softlimits so that X minimum is 0 and X maximum is 1000mm then Mach will niot let you go outwith this, same for Y axis
Now you then jog away from your G53 zero position to the corner of your material, say for example its 100mm on both x and Y and zero your DROs, this will now give you a work offset position of X0 Y0 and you can start your work from there. You can programme to move X and Y by minus 100 from this position but Mach will let you go no further, same applies for the positive direction, Mach will not let you go further than 900mm X and Y from your new zero position. This is because Mach still keeps a note of the "true" zero (G53) and works out your softlimits from there.
Hope this is clear and helps a bit with your question, if not ask away again.
Hood