To some extent, yes.
It applies the modifiers when the characters are generated, before prepare carefully gets to edit them. You can still make changes with prepare carefully, but after the pawn is generated its off-hands from the scenario parts (except for the death on explosion, which is activated when a pawn dies regardless)
Edit:
Also, modifiers for non-starting pawns (raids, random joins, etc) will be applied too, since they are generated after the game is started
It applies the modifiers when the characters are generated, before prepare carefully gets to edit them. You can still make changes with prepare carefully, but after the pawn is generated its off-hands from the scenario parts (except for the death on explosion, which is activated when a pawn dies regardless)
Edit:
Also, modifiers for non-starting pawns (raids, random joins, etc) will be applied too, since they are generated after the game is started