Well someone already posted this on that thread which is accurate:
"Yes it is definitely possible that low regen is better for range.
Actually it's most likely to be best. Low regen and coasting is giving best range for all EVs I've owned/tested."
Ideal regen for range is no regen (not breaking but coasting) because regen tends to be only around 30% efficient. Granted this is still very important but if you don't regen and use the energy to coast you are doing much better.
There's a "however", I think. I added this to the UK forum discussion
I expect that part of the question is "How do you drive" when in "High Regen"? Assuming that there is a High Regen accelerator "pedal point" that is equivalent to "coasting" and that you try to find that point and let the car do a long slow down (like it was coasting) when you see a red light ahead in the distance, it should be about the same. If you single pedal drive by driving "at speed" up close to the red light and then rapidly letting off the pedal so you decelerate "hard", then you'll get worse economy.
But, of course, I look forward to getting car back to test this for myself.
I did think that the discussion of whether you learn to "hesitate" to slam on the brakes in an emergency was an interesting point.
I used to have a Fisker Karma that had a flappy paddle to flip you through Light/Med/Heavy Regen modes. So, I developed the pattern of letting off the accelerator immediately upon seeing a red light change in the distance and use the paddles to effectively "down shift" towards a stop. But, I would do a bunch of "coasting". In surprise/emergency circumstances in ANY car, I still keep pulling at an imaginary paddle that isn't there (in my wife's car, I turn up the radio volume).
I have to tell you one thing I love about the Bolt is the “high regen” switch on the wheel. So instead of switching modes (low or high regen can be chosen) you can ALWAYS kick in full regen by pulling the switch to stop. Now I am addicted to that.
The Paddle Of Bog is too **** addictive. I still reach for the paddle in when approaching a light that changed unexpectedly. Even in gasoline cars and diesel pickups even. All EVs should have the Regen Paddle.