BDay is the only exception. If between your ITA and your AOR you will loose points because of your Bday, it will count as if you did not loose those points (attention, if you celebrate your Bday on the day of ITA, then tough luck there).
But for everything else (like validity of your IELTS, TEF, ECA and even 10 years backwards of your work experience). All those changes can result into your application rejection.
So for simplification:
Your Bday points will freeze at the day of your ITA
All other points will freeze at the day of AOR.
And you have to prove that at the day of ITA and AOR you were still eligible (you had enough CRS points).