Does a particle start its path decohered before it reaches what caused decoherence to trigger?

According to the math it does, but no one is getting how profound this is. Apparently, the quantum field knows of future decoherence events. Or coherent waves don't have a future time limit on becoming physical. Coherent waves are everywhere, including the future.

Could a matter wave that is going to decohere start its journey as a wave packet and then become physical at the actual decoherence event?

A wave packet is as physical as light can become. A matter wave is forced to use spacetime when a decoherent event is imminent. Wave packets use spacetime so there is a chance the particle is not truly physical until the decoherence event. The particle had to be a wave packet first because wave collapse wasn't an option yet. Do I dare say the decoherence event is wave collapse? Because the collapsed wave is allowed to continue past the event, it was allowed to dictate what the particle was in flight (decoherent).

Can wave collapse be the decoherence event that swaps a matter wave packet to physical particles? Is it still considered decoherence if the event caused the particle to dead stop?

So measurement does cause wave collapse, but the collapse goes from decohered wave packets to physical particles. Coherent quantum waves (plane waves) are not involved.

A wave collapse that doesn’t allow the particle to continue moving past the decoherence event will not be decohered wave packets in flight.

Is a decohered quantum wave packet, analog?