[QUOTE=HiYoSilver]Running a stop sign and transforming it to a yield sign is perfectly legal. I think not.

QUOTE]

In Idaho it is. See the attached piece of code

49-720. STOPPING -- TURN AND STOP SIGNALS.

A person operating a bicycle or human-powered vehicle approaching a stop sign shall slow down and, if required for safety, stop before entering the intersection. After slowing to a reasonable speed or stopping, the person shall yield the right-of-way to any vehicle in the intersection or approaching on another highway so closely as to constitute an immediate hazard during the time the person is moving across or within the intersection or junction of highways, except that a person after slowing to a reasonable speed and yielding the right-of-way if required, may cautiously make a turn or proceed through the intersection without stopping.
A person operating a bicycle or human-powered vehicle approaching a steady red traffic-control signal shall stop before entering the intersection, except that a person after slowing to a reasonable speed and yielding the right-of-way if required, may cautiously make a right-hand turn without stopping or may cautiously make a left-hand turn onto a one-way highway without stopping.

I agree with you regarding the need to be careful when splitting, however.