How to assign a confirmed user role upon email confirmation without logintoboggan?
If you're only allowing the user to login once they validate their email (which would make sense if you're using email confirmations) then you could just create a rule that assigns the role to the user when the user logs in:

{ "rules_add_user_role_at_login" : {
    "LABEL" : "Add user role at login",
    "PLUGIN" : "reaction rule",
    "OWNER" : "rules",
    "REQUIRES" : [ "rules" ],
    "ON" : { "user_login" : [] },
    "DO" : [
      { "user_add_role" : { "account" : [ "account" ], "roles" : { "value" : { "5" : "5" } } } },
      { "entity_save" : { "data" : [ "account" ], "immediate" : "1" } }
    ]
  }
}


Now, if you're allowing a user to login without having to validate their email (which makes less sense) then you'll need to write a bit of code that hooks into the user reset form and adds the role to the user when that form submits.