The point is well taken, Yes, it can make a difference when steering changes the curvature of the housing, which is why I preferred to explain how it might make a difference, vs. stating that it did, or didn't.

The question is whether it makes a material difference or not, which given that Shimano now uses spring housing in some kits, might be in doubt. Considering the small amounts that the handlebars are turned while riding, and therefore the small change in neutral axis length, I think that whatever difference there is will be probably be within the working tolerance of the system. But it might make the position of the handlebar when the derailleur trim is adjusted more significant, so I'd do so with the front wheel straight.

Also make note that this seems to be 4mm housing so any change in neutral axis length would be 25% or so less than with 5mm housing.


BTW- let me remind folks that while it might be OK to use spring (brake style) housing for the derailleurs, it definitely is not OK to use index housing for brakes. Index housing lacks sufficient compression strength for the brake lever forces and may burst in an emergency braking situation.