Another reason not to use a stud is how to seal the stud/nut thread against fuel leakage.
Also, with studs fitted, it would take a fair time to drain the bowl prior to removal.
For the countless times I have done up Holley bowl screws, I have never stripped one.
Having said that, I helicoil all threads in my carburetors, expecially early
zinc castings.
A helicoil is effectively like fitting a larger diameter bolt, so has more holding power under tension.
Gary