Ah, I didn’t realise post fader stereo auxes didn’t follow the channel pan. I’ll have to test that.
I imagine stereo FX sends would be the same, the main reason to use them would be so that if you have an input going to a reverb and you pan the input left there won’t be a “ghost” image of reverb still sitting in the centre. I can change it manually but it should follow. Maybe it’s like post fader send levels where the physical send level control doesn’t change but the resulting level does change.
Chris