The RB211 series DO NOT NORMALLY exhibit such volumes of smoke on start.
I have to smile when I see these statements.
What it
should read is...'do not normally exhibit such volumes of smoke, unless the ambient temperature at the airfield is quite low, and the engine has been cold soaked.'
Very common to see these engines smoke on startup, under the above scenario.
In addition, also under these circumstances, a wing engine will normally spool up faster, during start.
The proximity of the number two engine to the APU is immaterial.