What setting disables the naming logic when I want to reverse engineer relational model data? and what is the rationale behind the default logic (which removes s)?

I'm using v2.6 and would like to use v3. But before I convert a v2.6 project, I'd like to get to know v3 first.

you mean make a name singular? E.g. customers -> customer ? Both in the patterns for names (e.g the name of the navigators mapped onto one/many to one relationships: the $S suffix) and the plugin itself: http://www.llblgen.com/documentation/3.0/Designer/hh_goto.htm#How%20To/DisableNameSingularization.htm