You admit distribution is something that can increase over time, so it should be plainly obvious that capacity will increase as time moves on (as opposed to staying stagnant or slowing down), especially considering everyone involved in the process has explicitly stated it will.

The additional vaccines that are close to approval give us further reason to expect the rate of vaccinations to increase significantly.

We have no reason to believe the current rate of vaccinations will remain stagnant or slow down, and many reasons to believe it will increase significantly in the coming months.

That doesn't mean that you can't scale it at all, and one would assume that scaling over a super short period of time (like, weeks) is harder than scaling over a slightly longer time span (like months).

On that basis, is it not fair to assume that there'll be at lease some non-linearity in production and distribution rates over the next year or so?

We're only about half way done with this.