Ole, a couple of quick points.
First of all, I tried near focus and I tried far focus with the Rollei IR film. Notice I did not say that
no refocus is necessary, what I said is that I find it to be negligible. It was noticeably less of an issue than with other lenses that I have used... various schneiders and nikkors.
Second, the film I mentioned, Rollei IR, is a near-IR film... really what you might call edge red or extended red. I did not claim that there will be no refocus with a deeper IR film such as HIE or digital IR. But as you know, the basic issue here is
n as a function of lambda, and in an APO lens, you don't have n(lambda)=constant across the visible range and then suddenly, drastically, it goes to crap as soon as you get to 800nm. Again one has to bear in mind what lambda range one is talking about. With HIE and digital you are seeing out to about a micron or more. Not so with Rollei IR and SFX and all that.
I use apo process lenses for near UV and near IR stuff and have had good success, even working wide open, even using swings and tilts. People should simply try for themselves.
Couple examples where I was shooting a 360mm apo-nikkor wide open with liberal swings to test...
IR
http://keithwilliamsphoto.net/Photography with Invisible Light/Jacob Apo Infrared.html
UV
http://keithwilliamsphoto.net/Photography with Invisible Light/Jacob in Ultraviolet.html
In both cases the optimal focus was predicted by my ground glass to be dead center and then I made a line of good focus across each frame with a swing...