My mob's OM says flap full is normal - but flap 3 is
available at command discretion.
Economy is last on my priority list but during normal
ops and if the more important boxes are ticked, then
yes I'll consider the lower landing flap setting taking
into account any tailwinds, preferred runway exit etc
etc etc.
Airports with NA app - (eg BKK) - require flap 3 in
normal ops (lowest selectable landing flap).
(Why Bangkok I dunno, given the city and suburbs
combined is one big bloody noise factory anyway).