@Nanny-Martin 

I am using a Starlink Gen 3 Standard system for my Internet access.  I purchased a 3-pack of the X55 units.  I connected one of the X55's to the Starlink Gen 3 Router with the included network cable.  During the setup I was forced to create a Deco network.  Once the first X55 connected I switched it to Access Point mode.  I then placed and powered each of the other 2 X55 units.

1.  The satellite Deco obtain their configuration from the Main Deco unit, when being added to the Deco mesh.  When purchasing a pack, the satellite are probably automatically added to the mesh.

2.  The terminology is confusing.  In the context of the Deco, Access Point means the Deco does not handle router functions such as NAT and DHCP (assignment of IP addresses).  However, even in AP mode, the wifi network of the Deco is independent of any other wifi network.  The Deco mesh does not extend the existing Starlink wifi network, it extends the Starlink IP subnet.

3.   If by network, you mean wifi network, it is usually recommended to use exclusively the Deco wifi network.  That will provide benefits such as transparent roaming.

4.  You should rather disable the Starlink wifi network.

5.  You should not use Starlink wifi at all.  Deco does not allow splitting the wifi network.  If some device require a splitted network, you could probably use only 2.4 for the guest of the IoT network.

About whether to place the Decos in Access Point mode or the Starlink router in Bypass mode: either way, it is recommended to exclusively use the wifi of the Deco.

  @yves_b 

Thanks for your reply.  I have noticed that when viewing the network devices through the Starlink app that any device connected through the Deco network shows as Wired vs 5GHz or 2.4GHz.  I guess this is only because the Deco X55 has a wired connection to the Starlink router.

  @Nanny-Martin Indeed, as the Deco runs in AP mode, the StarLink router sees those devices as reachable via that wire.