I think the placement of WR703 is questionable: It is directly exposed under the hot air blowed from the heatsink, and 43 degree is not an ideal working temperature for such a small device without cooling. I have seen someone placed it outside of the box and that makes some sense
Same with PSU, it is located near the end of the heatsink where hotest air is sucked into PSU
Currently my unit is put on balcony and the temperature there is -2c degree, but my weather sensor still reports a 37 degree at exhaust
WR703 has an airflow so it's "cooled", even if temperature of the air is more than 40c.
PSU: probably the third fan gives enough air to it, module radiators are on the other side.
-2c => 37c
strange. This means that inside at 25c ambient it will have 64c exhaust (improbable).
Thanks for the time you took to take the high quality photos, johnyj.