It's probably easier to just torque those joints in the loaded position than it is to think about whether it is the problem, so I would recommend you do it anyway. BTW, what you really need to do is to torque them when they are in the same geometry when loaded. So you can measure that, remove the wheel, jack up the wheel to match that geometry, and torque them now that you have easy access.

EDIT - also, re-reading now. Your question is definitely valid, and your diagram is nice too. But I'd still proceed as I suggested above. BTW, my comments there on re-torquing are maybe more relevant to the rear wheels, which I thought you were talking about. I don't know if there are any clearance/access issues on the front wheels, or if you can just get down there, loosen, wiggle, and re-tighten.

But this experience I had may be related ... I had a RWD car (that simplifies things) that would always pull to one side. Multiple re-alignments, suspension checking, etc., and no change. Then a few years later, I finally found the right front upper control arm had a bushing that would hold position, and then could shift at higher loads, such as when driving vs. when on an alignment stand. So I replaced the UCA, and the car drove straight, finally.

So for a pull that starts at a higher speed like you have, I'd look for suspension components that may have marginally failed, so they seem solid enough with a quick lookover (which is solid enough for alignment and < 50 mph in your case), but may allow a deflection at the higher loading you get at higher speeds.

EDIT - since it sounds like this is a new problem that arrived after replacing many front suspension parts (right?), I'd double check all those installation points, as it sounds like you're doing. Are there any remaining components up there? Steering-related? inner TRE's? I'd be looking for a potential shift at higher loads. Good luck.

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2001 X5 3.0i, 203k miles, AT, owned since 2014