1) Yes, this is my mistake. Initially I got some misconception in MIMO and Dual Cell. Just realize recently after further my research in UMTS 3GPP.

2） Yes, Maxis did actually implemented dynamic APN for postpaid broadband and mobile internet. I can even connect with 'blacktubi' as APN. Just sometime most beginner users prefer to set a APN instead. Or I should say placebo effect.
Some plan like the old SKMM require 'bbnet' to be as APN. Therefore I keep this info there

Thanks for all these information