Description
The Stop Command Button is coded to trigger when you release "S".
But all units are also hard-coded to stop when you press "S", regardless if they have the Stop Command Button or not. So removing this hotkey won't have any apparent consequence for end-users, as units are still hard-coded to stop.
In 1.04 this results in units units stopping twice. Once when you press S, once when you release it. This only happens with units that have a "STOP" command button. So workers and dozers are not affected by the bug.
It is unclear to me if there are any related issues caused by this. Potentially.
It did cause issues in a custom map that I am currently creating and I don't think users would expect their units to stop twice for a single button press. It gets really obvious when you slowly press-release the hotkey.
Solution:
Remove "S" as hotkey for the stop command button. As this could potenially confuse new players who do not yet know command buttons, you should instead show in help text of command button that hotkey "S" exists.