This is a stupid question... But I was looking at the parts diagram for the motor on the B3350 and I see it has a mechanical injection pump with an electronic actuator for the fuel rack...
Is it possible to replace the electronic actuator with a mechanical governor setup from an older V1505?
NO clue and I don't own one but that looks like what the ECU controls. you might need also to replace the shut down solenoid or modify the wiring harness to control it from the key switch.
For the safety OPC control you would want to have switches on the PTO and seat wired to cut power to the shutdown solenoid ( assume it's set so the default no power position is to cut the fuel at the pump) That way you have ability to retain the engine shut off if you leave the seat for example and the PTO is engaged.
Thinking about it you should have something on the HST pedal as well so if the tractor is moving and your not in the seat it shuts off.
Also in another direction... would it help keep heat in the reformer and DPF by wrapping it with something like this...
https://www.summitracing.com/search/part-type/exhaust-wrap
Not sure if that would cause problems with the system getting too hot.
Again just some
Just some rambling thoughts...
Also the KEY reason I have an LX2610