Prime concerns
Going back to the simple normally aspirated systems.
When using the primer should the cylinder be flooded the fuel will run back into the hot air box just as it may using the throttle to prime.
There is no difference in that respect therefore whether OVERPRIMING using the throttle or the primer. Undertaken properly it is his view and mine that priming is best done using the accelerator pump which leads to better starts and is least likely to flood a cylinder. Most racing motor engineers i've spoken to hate the idea of neat fuel being sprayed into cylinders. Cylinder wash being the main concern. Also with a hot engine an exhaust fire is more likely even with light priming when using the primer.