Ok, I'm confused now. So the 5-min of warmup idling and the 5-min of cool down idling is worse than not starting it at all?
Even the Multi-Fuel Engine Truck Operator Manual, Page 15 (Mar 1977) states "Keep your engine running - idle between 800-1000 RPM - for short stops. Figure a short stop is anything up to 30 minutes. You don't do your multi-fuel engine any favors by shutting down and starting up again all the time. It works better and lasts longer under steady operation."
As for dust, yes I agree it can get quite dusty here. I would definitely plan to seek cover if I seen an inbound haboob, turn the tail of the truck into the oncoming storm, & after the 5-min cool down for the turbo, shut the engine down & wait for the haboob to pass.