I did the second mod to the Insight this past weekend. It has been very warm compared to most Januarys, so I went out and installed a clutch switch. Its not my own fancy 3d printed shift knob style, just a quick toggle that I put in. Its just hanging by my shifter right now.
For those who don't want to cut wires to the brake switch, I did as NoD did. On the B connector on the ECU, I pushed a wire in the back side of pin 14. That wire runs to the toggle switch, and then from the toggle switch it goes to a ground. This is IMO much easier than cutting and soldering wires.
For those who won't know, the clutch switch modification stops the car from using electric assist and regenerative braking. This is helpful when you are climbing hills and don't want to drain your pack. When your pack is drained, the car automatically forces regeneration to recharge the pack which can kill your mpg. However, you need to enable it when you want to use regenerative braking.
I took a spin with the mod over the weekend, but yesterday's trip home was the first real test. My trip home is mostly uphill and it really drains the battery typically. Yesterday was great though. I used assist a bit here and there, but arrived home with a nearly full pack which was even nicer for this morning's trip where I didn't have forced regen like normal. The trip to work today raised my average from 55.4 to 55.9 mpg.