Here is my take on why the insulation works.
when the engine is first started up all the mayo collects in the tubing. Since the engine and oil are quite warm, the mayo moves around a bit, from the valve cover to the oil pan and back again, all through the pipes, insulated or not. Once the engine is switched off, the cooling process begins, but also, the process of the oil (mayo) flowing back into the pan,through all the pipes etc. the insulation allows the mayo to circulate longer (flow back down into the pan) than if there were no insulation and the pipes would cool quicker. even a few extra minutes makes a difference! (molassas in january vs molassas in july!??)
While maintenance makes the most sense, getting rid of the mayo (technical term i know!!) is the root of the problem. the insulation allows the residual to flow into the pan rather than clog the pipes.
I agree that maintenance would be the smarter move, as would insulated (cold weather replacement) parts if needed. Ive also noted that the hoses covered with insulation have less "thermal shock" and become less brittle than ones not covered. rapid cooling and heating is what seems to make them weaker! just my $.02

__________________
2003 X5 3.0i (02/2003) sport package, Sapphire black metallic / Black Dakota Sport seats. compass mirror retrofit, trailer hitch retrofit, Prodigy P2 trailer brake controller installed, PDC retrofit, Lumbar support retrofit. heated rear seats retrofitted. Running boards retrofitted and subwoofer install in progress. 4.8is Brakes installed front and back. Bluetooth TCU installed, Rear Fog lights installed. Retrofitted reclining rear seat backs.