The torsion bar should be installed when tuning the length of the adjustable strut rods, you want the suspension as fully assembled as possible so the binding represents what will actually happen when the car is on the road. So I check for binding with the suspension fully assembled with the following exceptions- torsion bar adjusters are removed, shocks are removed, and the sway bar (if present) is unhooked.
Regardless, the torsion bars don't keep the LCA's from moving about (although ultimately they would keep the LCA from coming completely off the pivot shaft). The torsion bar socket and anchor are further apart than the length of the torsion bar, which is done intentionally because the torsion bar itself will shorten and lengthen slightly when it loads and unloads. But that also means the torsion bar wouldn't keep the LCA from moving back and forth a bit on the shaft.
The LCA's movement forward/aft is constrained by the strut rod. The poly and delrin LCA bushings do allow the LCA to slide on the pivot shaft, but the distance is controlled by the strut rod. Which is why I always recommend adjustable strut rods with poly or delrin LCA bushings, so you can tune the length of the strut rod to correctly locate the LCA and prevent any binding.
With the factory rubber bushings at the LCA and strut rod, there will be more forward/aft movement of the LCA at the outer ball joint than with poly/delrin bushings and an adjustable strut rod. That movement will all be flex in the rubber, but the deflection will be a larger distance (again, you can see that deflection in the video clip I posted earlier). And if the strut rods were removed, the LCA's could travel far enough to destroy the rubber LCA bushings.
The idea that the LCA can slide off the pivot shaft with poly/delrin bushings is just silly, the LCA's are constrained exactly the same way as with rubber bushings because the rubber LCA bushing does not constrain the forward/aft movement of the LCA. If you remove the strut rod you can pry the LCA right off the pivot shaft, even with the OE style rubber LCA bushings. It requires more force than sliding the LCA off the pivot shaft with poly/delrin bushings, but the amount of force required to peel the LCA off the pivot shaft with rubber LCA bushings is still less than what the LCA sees in use on the car. Regardless, only a fool would remove their strut rods and go for a drive, so it's moot to begin with.