To be precise the last person to do the first S/R doesn’t need to do it a second time. A classic pattern for this “full-sync” S/R would be:
A B C D A B C
(where A, B, C, D are the four users with anything other than Observer rights.)
(Note that not just translators can change data: non-translators cannot change books, but they can write Notes, approve spellings, choose morphological parsings, and edit entries in the Biblical Terms tool.)
But the order doesn’t have to be the same on the second round. It could be:
A B C D B A C
… the point being that once all four users have done an S/R, all their changes are then stored on the server. The second time around, everyone gets all those changes – but D doesn’t need to do that, because he/she got all of A, B & C’s changes at the same time as he/she uploads their own.
After that, all the Observers can do an S/R and get those changes. So, if E, F & G are Observers, you would do:
A B C D B A C ; E F G
@anon291708, correct me if I’m wrong on any of these points .