When I donate I can type in "1B" and there is no error message, but in fact it is stripped of that B and I donated 1 instead of 1.000.000.000 ... yeap, donating 1 Credit in base log looks epic

... is it possible to change behavior of those editors (most important are those for donation/contribution)?
As we see most numbers in K/B/M I would like to be able to type numbers in that format too

What's wrong with typing out all the numbers? 1,000,000,000 isn't hard to type.

Yes, it isn't hard. And this suggestion isn't critical as only some weird cases can cause players to feel harmed by it. So it merely about consistency. Actions should generate expected results or (descriptive) error messages.
So:
a) K/M/B should be forbidden (don't validate / match pattern... implementation isn't important)
or
b) K/M/B as suffix should evaluate to *1000 / *1000000 / *1000000000 <-- this solution seems "nicer" as game communicate with players using K/M/B