mneeth

Excellent work @Wiggly Electron and thanks for sharing with the community. The most reliable way to objectively know if your appliances are squealing at 15kHz is to use a sound spectrum analyser app on your phone. Most good cell phone microphones are sensitive to frequencies up to 20kHz. The older you are, the lower the frequency threshold of your hearing, this is a natural process. My kids can hear sounds above 20kHz. I used to be able to hear those. My hearing limit is now around 16-17kHz, so I can just make out the Deye/Sunsynk hum on our appliances. This is a screenshot from an app on my iPhone, you can clearly see the spike at 15k when the phone is near an appliance.

I must correct myself. After updating to version 3384, a new option appeared.
Settings -> Battery -> Page 2 -> Low Noise mode

Enabling this setting shuts the inverter down, "Grid Mode changed" appears on the screen and after roughly 1 minute it turned on again. Now the frequency is moved from audible 15 kHz to barely audible 20 kHz. This is a very huge improvement.
 

Thanks for all your input. In the end, I went with 2 x 5kW inverters giving me 4 separate MPPTs. I have 4 strings now, 2 facing north (8S each) and 1 facing east and west each (5S each).

Thanks for all your input. In the end, I went with 2 x 5kW inverters giving me 4 separate MPPTs. I have 4 strings now, 2 facing north (8S each) and 1 facing east and west each (5S each).

Thanks for all your input. In the end, I went with 2 x 5kW inverters giving me 4 separate MPPTs. I have 4 strings now, 2 facing north (8S each) and 1 facing east and west each (5S each).