Just thought I'd throw in a word here.
Since the last patches it doesn't seem like this works for me anymore no matter what affinity I set it to, the process is still started on the first core. I'm thinking this is possibly because of the update to the ogre engine that FH runs? Still able to use this on other software and programs.
If this is just me then I will just have to live with it, would be interesting if anyone that used to use this could try it again and see if they get the same result since I'm not sure if this method even works anymore.