This last week, I visited a shop that dispensed 212F water into a kettle and used that to brew on a Kalita Wave. The thought being that by the time the water hit the kettle and then was dispensed to the open-air brewer, it was about 203F.

Then, I read (One of) Scott Rao's criticism of the Chemex and it's inability to hold brew temperature due to a large surface area exposed to the air and a longer brew time.

I have an electric Bonavita Kettle and for these reasons, I have already bumped up my brewing temperature to 207F, but I'm wondering if I need to bump it closer to the 211-212F for Chemex. What do you all do?

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You bring up some good points. I would think the ideal kettle temperature would vary according to roast type (assuming other variable such as grind remain the same). Lighter roasts typically achieve their best results at higher temps while darker roasts require lower contact brew temperatures.

Experiment with one coffee and don't assume that temperature is ideal for all subsequent coffees and roasts.
Having a temperature controlled kettle definitely helps out here.

I've read Scotts's comments and all I can say is that if he can't get great coffee from the Chemex, he is doing something wrong.

My daily routine:

Fill Bonavida stovetop kettle and place it on the stove to boil.
Place a Chemex unbleached square filter into the Chemex
Grind 45g of coffee and place it in a Kone metal filter, tapping the point on the counter to pack and settle the coffee bed and set aside.
Grab my Brewista scale and place the Chemex on top.
When the water is at full boil, pour some into the Chemex filter to rinse paper and warm the glass.
While the water filters through, fill the Yukiwa
Place the Kone w/coffee into the paper filter.
Remove the paper and Kone together (Kone keeps the paper from folding up), dump the rinse water, and rinse Chemex again with remaining water in Bonavida.
Replace the Kone/paper filter assembly.
During the 30 seconds it takes to do all this, the water has cooled to about 203* and I tare the Brewista, start the timer and start a slow drip, Kono-style pour. For a darker roast I'll let it cool to below 200*.
I try to complete the 750g pour in 3 minutes.
When it's all done I dump the Kone of spent grounds and rinse the Chemex filter to reuse again. I get about 8 cycles per filter.
If I've poured slowly enough, there will be fewer fines on the paper that made it through the Kone.

Oh, and you have to find a friend to sew you a nice Chemex cozy. You can see mine in my avatar. It serves double duty as coffee warmer and clumsy insurance.

Actually I've found that the bonavita holds heat very well if filled to the line. I think since the entire unit is heated.

Water temp hits the coffe about 3f lower than set temp and you lose about 3f during a brew.

Are your brews bitter or sour? Also grind size plays in.