Update, with one new piece of information that I think narrows this down.
A player on PC, Viscenzxo, opened a separate report titled "Analog sprint trigger linear curve" describing the same behaviour in almost the same words: with Analog Sprint ON the trigger response curve is no longer linear or incremental, and any press past roughly 15 percent already triggers maximum acceleration animations and heavy touches, which makes feathering the trigger impossible. He asks for the trigger sensitivity curve to be recalibrated to match FC 26's response depth.
That is PC, with a different controller. Mine is PS5 with a standard DualSense, and my threshold is around 20 to 25 percent. A third report, by MemberFC26, lists PC, PlayStation and Xbox. Pvt_GosIing, who posted the Input Overlay clip here, is on a standard PS5.
So this is not specific to one platform, one controller model, or one player's hardware. That leaves the trigger response curve in the game itself.
I have left a comment on both of the other reports pointing people back here, as EA_FieryHelios asked on the Steam forum, so that the observations end up in one place.
For completeness: the behaviour is still present after title updates 1.0.1, 1.0.2, 1.0.3 and 1.0.4. Analog sprint is not mentioned in any of their notes, nor in the gameplay developer launch update of 30 September, and 1.0.4 states explicitly that it contains no gameplay or balance changes.
Could someone confirm whether the FC team has had a chance to look at this yet? Twenty-four days in, the question is still open.
