The original beta WUs had a 48 hours delay.
The very short ones are "repair" WUs which are scheduled on 20 % of the original delay as usual, that is only 9.6 hours!
But now I hope that most worried beta testers are aware that it does not matter, and knreed has posted in another thread that they will be credited until 5 days after the deadline.

Regarding the preliminary warnings to beta testers you are right and we will try to not forget to remind the techs about it for the next beta test. Which should start pretty soon for Linux and Mac machines (personal guess, no guarantee).

Cheers. Jean.