Power of two reallocs are usually there to prevent append in a loop from becoming accidentally quadratic so I guess it's either a bug or a feature depending on if you're going to do that.
As long as there is a non-zero multiplier, it does not matter the size of the constant factor, and it does not even need to be constant. I spent a while recently looking at the shape of this non-typical allocation growth curve, which ended up going with `n₁ = n₀ + 4n₀^(7/8) + n₀/8` using only integer math:
// compute maxsize = maxsize + 4*maxsize^(7/8) + maxsize/8
// for small n, we grow faster than O(n)
// for large n, we grow at O(n/8)
// and as we reach O(memory) for memory>>1MB,
// this means we end by adding about 10% of memory each time
https://github.com/JuliaLang/julia/pull/40453/files#diff-fb6...