The best would be to add one more H2D, also known as Nest Wifi router, in my opinion. It will perform better than Nest Wifi point and Google Wifi. Adding it will be just as adding any other unit to an existing Nest Wifi network. Set up instructions:
The newer Nest Wifi Pro is not backwards compatible, so unless you plan to replace your existing unit too it is out of the question.
You can compare specifications here:
I don't work for Google.
