As the device doesn't need to be fitted to the bike once the flash has been applied I don't know where the failures occur or what the failure mode is. I didn't find anything negative when I was looking at which tuner to go with.

For the record I have my oil temperature set to C and it shows around 107 on a hot day.

 

Rather than adding an oil cooler I'd run synthetic, it will handle much higher temps without breakdown...have been running Mobil 1 V twin 20W50 in my Norton Commando for about 8 years and it has been trouble free, and will switch to it for my new to me Sportster when I change the oil. Here is some info from Mobil's FAQ
(I have no connection to Mobil)

https://mobiloil.com/en/faq/product-...View=20&Page=1

How is Mobil 1™ V-Twin 20W-50 motorcycle oil different from Mobil 1™ for passenger cars?

Mobil 1™ V-Twin 20W-50 fully synthetic motorcycle oil is designed for air-cooled, large-displacement bikes. Because of their design, these engines can generate very high localized oil temperatures and high overall bulk-oil temperatures. As you know, a typical air-cooled V-twin's rear cylinder gets a lot hotter than the front cylinder – it's a matter of airflow. When it's hot out and you're stuck in traffic, the oil temperature in your bike climbs rapidly. Above about 250 degrees Fahrenheit, conventional motor oil is going to break down. Mobil 1 V-Twin 20W-50 fully synthetic motorcycle oil is good to above 300 degrees Fahrenheit. Like Mobil 1 Racing™ 4T 10W-40, Mobil 1 V-Twin motorcycle oil has high levels of phosphorus/zinc and the same high-temperature detergent technology for superior wear protection and engine cleanliness, even at elevated oil temperatures. With Mobil 1 V-Twin motorcycle oil, you can go the full length of the manufacturer's recommended oil change intervals with ease.

 

I am running a synthetic oil, a true 100% synthetic oil. Currently it has mixture of 2 qts of Redline 20w50 and 1 qt of Redline 20w60 in it. If I'm not mistaken Redline has higher levels of zinc and phosphorous in it than Mobil 1 does. Redline has 2125 ppm of zinc, and 2100 ppm of phosphorous. I would like to see oil temps closer to maybe 220*F @ 70 mph.