In my comment I wrote just three sentences. The middle sentence starts off "Even the original M1 MacBook Air..." Then the link I provided is to an investigation on charging speeds of the MacBook Air.

That link shows that it's using >45W while (potentially) powered on and doing things other than charging.

Apple supplies a 30W charger in the box, so I think it's fair to say that a third-party 30W charger is "full speed" (in the sense of "as good as the stock one", if not full speed in all potential scenarios GP might or might not care about).

Full Speed to me means as fast as the laptop will allow, not as fast as the one that came in the box.

That is not a reasonable definition of full speed. You would seriously say out loud that a 45+W charger “charges the laptop 50% faster than it charges at full speed”?

No, but in some context I might call 30W "full speed" and 45W "turbo speed" ;)

Apple supplies cheaper macbook pros with a less than full speed charger.

When iPhones shipped with chargers they were only 5w despite being able to charge from faster chargers.