A picture really interesting. Thank you very much.

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1. Right.
2. Is an efficient way to power the plates lights with
the original wiring when making this modification to install BCM Max on
6R Europe (2009-2014).
Note: bla,bla,bla..... in the easiest way possible.
In your original wiring without BCM Max, light switch output T17/16 feeds or
provides signal to several systems. Among others, Dimmer T6/3, BCM T73a/45, and
license plate lights.
Therefore... as clear as water, ... during the process you already have isolated the other systems
in your original installation without BCM Max, except LPLs.
The trick is
perfectly ready to be used.
3. Isolate.
Yes. Exactly the same connections.
It's correct.
The numbering written on the relay adapters is not the key, there are several identical or similar adapters with different slot numbers.
The important thing is written on/beside the relay pins (and lateral scheme).