You could with some eventing. The starting position would not actually change, you would need to start with the screen faded out and transfer them to the correct starting location based on a global switch or variable.
Viewing post in [CGMZ] Global Data for RPG Maker MZ comments
I had one global switch 18 for testing, now when I change that switch in the global switches list in parameters to lets say 8 or add a new global switch 20, nothing of these works. Only if i use switch 18. I copied the exact same parameter list and events to a new project and then it works. However, in the actual project when i disable all other plugins, still the same result, so can't be an issue with another plugin either. When i do a manual save instead of the plugin command to save global data, it does work. Can the global data be corrupted or something? Edit: Dev helped me through Discord, thx!