My experience sitting on the stone and concrete front steps on a warm sunny morning,
feeling all the radiated heat around me, makes me think where I'm sitting, wouldn't be
a good location for an outdoor unit on a day when I wanted to cool the house..
But, you are likely correct.. Maybe the sun directly on the unit doesn't have any effect.
During the winter, one would think the sun would help melt the ice on the HX,
but the air temperature is going up when the sun directly on the area..
My outdoor sensor under the deck is out of the direct sunlight, but it always
jumps up when the sun light moves into the general area..
(that's when comparing the sensor under the catwalk, with the 2nd sensor that is
located well away from any change of solar warming).
In the spring time, I've measured the decking at 140 to 160 deg F, while
in direct sunshine. So, I would think that a light (reflective) color on your
outdoor unit might keep the metal case under 100F..
~~
The reason for bringing air from under the deck & den, would be to
get a source of air without snow.. When snow is sucked into the air intake,
it causes the system to use more power and can shut it down, eventually.
So, the goal is clean air.. This video shows the intake, with the fan off..
https://youtu.be/F3dGciqRRCM
Snow is the enemy of the ASHP..
When it starts snowing a lot,
I start thinking about a GSHP..