This issue is present via ACR, SilkyPix and JPEG. SilkyPix and JPEG produce such impaire sharpness that that the evidence is less obvious, but it is still there.
See yesterday’s discussion of the Fujifilm X-E1 artifacting issue, which is identical to the Fujifilm X-Pro1.
Just published in my Guide to Mirrorless is an Fuji X-Pro1 artifacting example that I shot previously with the Fujifilm X-Pro1 back in September, shown below. The example shows several very large actual pixels crops, as well as the original image at large size. Processed using Adobe Camera RAW.
A small actual pixels crop from the above: