Obviously the CHMOD 777 command did not work, which is why I asked the question when I was stuck being unable to execute the miner software. I still don't understand why, but no problem, it will eventually become clearer.

I had no idea what CHMOD 777 does, I just knew it because some customer support person told me to use it when I had issues with a VPN not wanting to cooperate.

That is of course very sensible advice, but I have already added several fans and built a contraption that will let me test what kind of fans and fan speeds will work best for various conditions.
When I use the Full Package Apollo (with my contraption) and set the temperature curve to 65/70degC, the built-in fan continues to run at around 1800rpm and the temperature stays below 60C, but I can still hear it. It's much quieter, but not as good as what I am aiming for.
But with the Standard Apollo I cannot (yet) set the temp curve even a little higher to get the built-in fan to spin at it's apparent minimum speed of 1800rpm. So it is louder than a Full Package Apollo with the same added fan contraption.

The contraption has 2 SPDT switches and 2 trimpots to adjust the reduced fan speed for 2 fans. It put's the power supply under the Apollo and uses exhaust air from the power supply to cool the Orange Pi. That might be a bad idea, but I will soon have some measurement data to clarify that.