Meridian 218 driving 5200se’s, DSW subwoofer, Roon+Nucleus

I have two questions. One about the connection the second about the 218 end.

The set in the manual says to use speaker link bottom out to the Master 5200
The Top speaker link out to the DSW subwoofer in
The DSW subwoofer out to the Slave 5200
218 via network/Roon/Nucleus
First does that sound like a good configuration for best sound? I never went through the subwoofer this way before?

Second swapping the 218 to a 818v3 in this set up which is two channel only make any sense from the prospective of the sound with this set up. I know its in another class from the 218 but does it make sense in this set up.Would the improvement in sound make a worthy investment?
Ag insider logo xs@2xtonycorvette1