Everything on my ignition is still automatic except glowplugs. Using manual control allows people to run other good glowplugs that dont swell. You can make it so that you flip a switch to control between automated or pushbutton glowplugs but i dont trust any variance of controller for these. Last idi was 94.... 8 year old minimum technology that isnt cheap and could kill all eight glowplugs. Most people love how simple IDIs are. A button is pretty simple, cheap, reliable.
One could steal an idi with a strand of wire. You can run ip off of a toggle switch, glowplugs and starter on a momentary. No brains to complicate anything. Ive also rigged a toggle switch under the hood so i can be under the hood while it cranks over.
Dead man switches and other crap will not stop any would be thief that knows about the truck. I have started and driven my truck without keys, a piece of wire, and my knife. Take wire, expose ends. Manually trigger glowplug relay for several++ seconds, then nip the wire in three if you have an e-pump, otherwise two. Expose new ends. manually jump epump from relay to hot, just wrap wire around stud and run it through the relay blades' hole. Then pop fss off ip and run wire through the hole on that blade terminal, wrap on pos.
Then jump starter relay and hop in, drive off. Takes longer typing than doing and is good food for thought. Can be useful too if you lose the keys while camping / out