Sorry, I misunderstood your first question.
On my NIW receipt, there is no A#
On my NIW-based 485, there is an A# (start with 088)
On my EB1B receipt, there is a different A# (start with 135, according to PJiang it's an temporary A#). The approval notice of this EB1B application shows the same A#.
When I filed the second 485 to be linked to my approved EB1B, I used the first A# (start with 088). So, the EB1B-based 485 receipt shows the same A# as my NIW-based 485.