Just an update po, after I submitted the explanation letter last thursday Nov21 (why I only submitted statutory declarations in the initial application) I finally got the positive result today Nov25.
So my view is that you can really get the result as early as 4weeks.
Oct15 - Submitted ACS application
Nov13 - CO requested missing document (Explanation Letter)
Nov21 - Submitted Explanation Letter + Statutory Declaration
Nov25 - Result Letter (AQF Bachelor Degree, -4yrs from exp)
Thank you @ms_ane for the guidance!
God bless to all applicants! :smile: