"I understand why the fuel pump cut-off is a safety feature (in case of collision, etc.). But don’t get why continuing current to the choke would be, other than running down the battery (?) Would it possibly ignite gas fumes? If so, that would make it dangerous in normal usage situations, and thus not a common feature."

It is a safety feature.

I posted the wrong schematic (the correct one will not upload for whatever reason).

Study the schematic without the oil pressure cut-out switch and that will isolate the coil circuit away from the IGN circuit.
You don't want to overload either circuit running in an older IGN SW/wiring system and you don't want the choke drawing power from the IGN circuit, especially after having gone to electronic ignition.

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i assume the cutoff for choke is just a good safety step. remove a hot wire from a supply of fuel. plus a length of wire that could pinch chaffe short etc.
Seth