I'm stealing this idea from someone on this site, but what I do is put my strike water in the cooler when it's about 5 degrees warmer than needed. Put the lid on for a few minutes and then check the temp. If at the right temp, I add the grain and mash in. If it's still a bit warm, I stir the...
The problem is that this ignores the effect of surface area. For chilling hot wort you may be correct (though even there you'll have diminishing returns on temperature difference vs surface area). When passing cooling water through a pre-chiller coil you have a little different situation...
Running the 2 coils in series through the ice bath should make a big difference in the temperature of the water entering your plate chiller. The design parameters for a heat exchanger are temperature difference and surface area. Running the 2 20ft coils in parallel gives you a higher flow rate...
I don't know if it's good or bad, but that sounds similar to the schedule I usually end up with. I do find it pleasant to be out in the garage late at night brewing. The only problem I run into is getting out of bed the next day after I stayed up till one or two in the morning...
I would also eliminate the dumbell on top of the orange coat. It's compressing the insulation and acting as a giant heat sink in the warmest area of your kettle. There's got to be a better way to hold everything in place.