Enclosing the previous log from mine these modulator only answer question without show the entire picture mostly (nothing personal here).
Maybe I elaborate a bit more:
PYNQ overlay is a high-level idea under python control.
If you design to have sensor or control below 100ms after powerup than my log post is what you want as it can bypass any unnecessary delay and just run things on FPGA alone.
But if Linux control is what you expecting than this is what the boot.py you want as now brown-out power on consideration aren’t the case here.
There are many application for example Over-the-air firmware updates or other same concept.
Cloud FPGA like AWS services.
See the detail can correct me if this is not your case.