A.W., agreed.
A change of OAT does not invalidate the AST result, and the calculated numbers remain valid. By necessity of how the figures are determined.
Although RTOW charts may exist with dual configuration printed on them, this does not change a thing.
It is entirely possible a Perfo SW suite could come up with a different configuration due to OAT adhustment, however that is also awailable for manual calculation if you decuded to dive deep enough.
The back office / mainframe or EFB calculations cannot provide any better results over the printed RTOWs. As the RTOWs are in fact a result of the same calculation core (SCAP module they used to call it).
The differences between the RTOW pre-conditins and outside world of the day will require applying corrections which are fixed to the most critical situation and thus overly conservative for 98% of the chart. And combination of corrections makes it a lot worse. Altimeter indication cold temp I chose on purpouse because it is hidden from the reader in the standard layout.
That is when the EFB delivers with pride, QNH of 1013 should not really be -1100 kgs penalty compared to 1013.25.
Second question, absolutely yes. Try a search for 'improved climb'.