Dear Shri Sravna,
The above gives an impression as if the NB is like a very old and nearly vegetative grandfather/grandmother in the family. Such people will not be usually aware of whatever is going on within the house and, for practical purposes, many goings-on in the house/family will be non-existent for them. In what way then is this NB (which is supposed to be pure knowledge, consciousness, etc.) different from such too old people, when you say that the NB is not aware of the "reality of saguna brahman and maya and space and time however is non existent to nirguna brahman"?
Now, you say that " the reality of saguna brahman and maya and space and time however is non existent to nirguna brahman". So, when finally this SB, maayaa, space and time, everything merges with that NB, how will it accept these? Will it not be shocked to see all these unknown & unbelievable guests suddenly coming into its home? Secondly, does not all this kind of imagination make NB, SB, maayaa, space & time etc., etc., different realities of independent origin existing alongside one another? Which means so many realities instead of not-even-two (advaita) realities?