Depending on where you live, and the electrician, I believe if you are using a 20 amp outlet, I think the code requires a 20 amp breaker. If a permit is required, then an inspection might be too.
In 2013 I qualified for an energy assistance program that included a new furnace. Because the box with the power switch was about a foot lower, although I don’t think it would have mattered, they had to have a licensed electrician come in to run a piece of conduit, 2 wires, and put in a second box with the switch. They used two wire nuts and put a cover on the original box. My understanding was that an electrician was required either way. That the furnace guy was not allowed to do the wiring. I later received a letter from the inspector, giving me the option of an inspection, or I could sign off as satisfied. I choose the later, as I ran the 220v for the dryer, and as I didn’t have a conduit bender, I used a separate 90° elbow, which while being completely safe, might not have been to code. Seeing as it was a short run right of the breaker box, and obviously newer than all the other wiring, I didn’t want some over zealous inspector asking why there was no permit.