You can safely cut the bottom pin off the 14-50 adapter. It is an unused neutral pin, (no electrical connection inside the adapter) and this is the only difference between a 14-30, 14-50, and 14-60, so once removed it'll now fit all 3 outlets. Just be sure you dial your amps down to 24 if you are using a 14-30 to avoid overloading the circuit.
can safely cut the bottom pin off the 14-30 adapter to make it more universal?