After contacting support regarding the annoying loud fan noises the support requested a video of the fan noise... At this point it was clear that a refund will not happen from the seller :D Best way would be to send it back and get a used ReefLed90 for the same price.
So i took care of this by myself.
Two solutions tested: At first i welded in a 50 ohm resistance in front of the fan to drop its rpm. Still enough fan performance (fan goes on an off, which means it lowers the target temperature enough to shut down) while having a great improve regarding the fan noise.
Second solution: Changed the Fan to a standard 60mm axial computer fan. I know, not perfect regarding the general design of the light, but still enough air for sufficient cooling:
I also added 12mm spacers to increase the gap between the light and the mounting arm, because it covered the majority of the fan:
Im new to noopsyche LEDs, but it seems that the previous V2 model hat a normal axial fan, not this radial riot thing...