For those of you struggling with WiFi performance on the 4Plus:
1) you can move the factory dongle from the mother board up to the external USB port. That helped my signal issue, but I was still only getting -63 dBm signal strength. That’s still abysmal, but it was more stable than before.![]()
2) You can heed the advice and get another dongle. Not being someone who follows instructions well, I ordered the non-Namo AC600 and plugged that into the external USB port. 

That resulted in a MASSIVE improvement in the signal. It’s now showing -34 dBm.![]()
I also wrote up my initial signal findings on here: . https://blog.daviddemartini.com/testing-qidi-4plus-wireless-performance/
What was taking 10+ min. to upload to the printer from QidiStudio, now takes about 10 seconds.
It was plug and play. Restarted printer after swapping the dongles and everything just worked.