I have sky Q in 3 rooms but coverage for my broadband is not good and I have ultra fast 500mbps despite 2 boosters im lucky to get 100mbps. As I move large CAD files I need the speed.

I was reading up on getting an x20 3 pack plugging one deco into my sky router and then disable the sky wireless to allow the mesh to do its thing..... will this work? I am hearing horror stories that the sky system has a protocol that won't let other systems engage with sky? 
can someone please clarify that the suggestion I've been told would work

Stephen