Charge mode while speeding/maybe worth it?

If frequent CHG mode does damage the traction battery then just hope it will destroy the traction battery which may not likely be the case. Just reduced EV range and capacity due to degradation will not be covered under the battery warranty, as stated clearly in your warranty booklet. Also, since your PP is pre-2020 and since you are not in CARB state, the traction battery warranty is 8 years/100Kmiles, instead of 10yrs/150kmiles.

 

Why do they have CHAdeMO in other markets?

Any type of fast charging causes more wear and tear on a battery. Toyota has taken steps to mitigate it. The CHAdeMO rate greatly drops when the charge level hits 80%, and charge mode only takes the battery to that charge. The system will also slow down, or stop, the charging if the battery is too hot.

You may not see any signs of degradation in the time you own the car, or you maybe you will. The potential damage isn't something that happens quickly. Just living in a hot state could cause degradation without using charge mode. There is lots of variables involved.

What is known is that most of the plug ins that do have higher than average capacity loss were ones seeing a lot of fast charging, which is what charge mode is.

 

Relying on GOM to document the traction battery degradation is probably the least reliable way. Here is my data set of GOM indicated EV range after the traction battery was fully charged. The data was from my 2017 PP when it was 2-3 years old. Yeah, if GOM is a good indication of battery capacity or true EV range, then my 2017 PP traction battery was getting better and improved as it aged.



Instead, a much better matrix to check for the traction battery capacity (or degradation) is the number of kWh used to charge the traction battery from 0% to a full 100%. As you can see, my 2017 PP lost 4-5% capacity (from ~6.7kwh to ~6.4kwh) in ~25 mo.



Similarly, you can also document the degradation of the traction battery by recording the real EV range (not GOM) from 100% charge over time. However, since in my climate, there is a very strong seasonal variation in the EV range, it has to be compared over more than 1 year for the same month to be a valid comparison. Unfortunately, I did not keep such data for my 2017 PP which I kept for 3 years. The data for my current 1-year-old 2021 PP looks like this. Not much degradation for the first year other than the normal seasonal changes.