In my case it shouldn’t be an issue. The controller faces west and my back yard neighbor’s two story home is appx 15 ft above my homes elevation. Even during these long summer days the only time it has direct sunlight is a brief period as the sun is setting. It probably gets hotter in my garage which faces east and gets hours of direct sunlight on the doors and no chance I’m putting it inside the house. Granted its only 81 F outside right now but the cpu reads at 55 C.
Also I’ve had a wireless router with an older ARM chip in it running DD-WRT, mounted outside in a similar outdoor enclosure on the north side of my home with no ventilation besides drain/wire holes at the bottom for a few years now and it hasn’t failed.
To be honest I was a bit surprised at that other thread asking about locking up/heat issues. Embedded processors get put through the ringer in testing due to the fact that they are often used in industrial situations… I believe I read at one point that the pi was run inside an oven at 176 F by the pi foundation for a significant amount of time without issue.