When I studied Hilbert space as applied to differential equations, I saw a perspective in which boundary conditions constrained the solutions in the same way as the differential equations themselves.
Physics has benefited in seeking simple differential equationsâ€”as simple as possible, but no simpler.
If this is applied to boundary conditions, such as initial conditions, then the uniformity argument for inflation is removed.
I have debugged numerical solutions for several sorts of partial differential equations.
I always start with uniform initial conditions where I know the answer and find the majority of my bugs there.
I am thus not surprised to hear that our universe seems to have started smoothly; I would have expected as much.

I recognize that this is a week form of argument, but it feels to me as strong as the arguments for inflation.