Hi  @comm3000 

Welcome to the community!

Yes, all of our Deco Mesh models are compatible with each other and can be conveniently added to your existing Deco Mesh Network via the Deco App.

Yes, you can install the BE63 as your main and XE75s as satellite nodes using the Deco app

Adding another Deco node will definitely make a difference in coverage, since it will allow you to relocate your existing nodes to new, further and more spread out locations. Exactly how much of a difference it will make will depend on a multitude of factors, including, but not limited to:

1. Where is the main node placed? 

2. How many sq ft are you trying to cover?

3. How many walls, and of what material, are obstructing the connections between Decos?

4. How much farther away are you trying to extend the connectivity of your Mesh Wi-Fi Network?