X-Rite support asked the same question -- why print with ACPU? I personally don't, but I have to support clients of our printshop with custom profiling so they can proof on their printers for large format prints that we'll later make for them on our equipment. Getting them to install i1Profiler just to print targets (while permitted by X-Rite license terms) is more complex and ripe for errors.
A very simple target-printing app like ACPU that runs on Windows and Mac is exactly what's called for when supporting multiple clients off-site. Except that app doesn't work quite right due to the scaling issue, as we know. It would be nice if Adobe would fix it, or if X-Rite would make the i1io a little more robust in auto-detecting a slightly off scaling factor. But the work-around of pre-scaling the target TIFF images is a small enough hassle that it will suffice for now...