Are you using an Adj gas block?

[TCBM]

The main reason not to use adjustable gas if you don't need it is port erosion.

You just took an open port and put a choke over it, turning it into a combustion chamber rather than the outlet for a manifold. There are ways to counteract that with nitriding and other processes, but I personally don't use Adjustable Gas if I don't need it.

I have had to use adjustable gas ports.

In other fields, gas erosion is caused by temperature and mass flow of the gasses. The temp and mass flow rate implies a BTU content that heats small portions of the steel to the melting point, briefly. Restricting the flow rate of the gasses reduces the total heat (BTU) applied to the steel around the gas port. As the flow approaches zero, the gas port conditions approach that of the rest of the barrel. It seems very unlikely that restricting gas flow with an orifice would increase the temp of the walls of the gas port, an orifice itself.

This is less like putting your thumb over a hose end, though both reduce flow, because a gas is compressible and does not increase velocity (almost) proportionally the way water does.