hello please, what is the purpose of dry run without machine lock ( lathe ) ?

about mills, i was told that there is something possible, like starting a program in dry-run while having z axis raised, then, when needed, z axis and speed, both will go back to normal

so i thought that, also on lathes, i can start a program like this, then disable this mode, and continue at normal speed, but once i disable it, also the program resets; i guess it is there in order to proof a program, but i am not sure

i use dry-run and lock in order to check syntax errors inside a program, or to find the restart number; i never used only one, but always both, and it kicked me a few seconds ago, that there may be something that i don't know / kindly