I think you have a misconception about what Semver is. No, changing private interfaces does NOT increase major version - why do you think that Semver specifies that you must declare a public API? This would also mean any bugfixes would result in major bumps, but they don’t, because not every interface change is treated equally.
You also skipped the actual question. What are all of Firefoxes interfaces? Is user flow itself an interface?
I think you have a misconception about what Semver is. No, changing private interfaces does NOT increase major version - why do you think that Semver specifies that you must declare a public API? This would also mean any bugfixes would result in major bumps, but they don’t, because not every interface change is treated equally.
You also skipped the actual question. What are all of Firefoxes interfaces? Is user flow itself an interface?