Isn't there some place where one can configure how closing dates are set for new students who've already missed assignments? What config file is that in? I've checked the files in webwork2/conf and can't find it.
There is no such setting for webwork2. In fact, that is a setting that I have never seen in any online homework system or LMS.
Adding students accounts automatically through LTI has the option to extend due dates at the bottom of the file authen_LTI.conf.
# When users are added to the system they are also assigned all visible sets
# This routine can be used to modify the sets before they are assigned. E.G.
# extend due dates based off the number of problems students have to do
#$LTI_modify_user_set = sub {
# # The self object from LTIAdvanced.pm
# my $self = shift;
# my $globalSet = shift;
# # The userSet object to be modified
# my $userSet = shift;
# my $numberOfSetsAssigned = $self->{numberOfSetsAssigned};
# my $daysPerSetMakeup = 2;
# my $reasonableNumberOfDays = $numberOfSetsAssigned*$daysPerSetMakeup +1;
# if ($reasonableNumberOfDays < 2) {$reasonableNumberOfDays = 2;}
# my $niceDueTime = $globalSet->due_date + $reasonableNumberOfDays*86400;
# my $niceAnswerTime = $niceDueTime + 600;
# $userSet->due_date($niceDueTime);
# $userSet->answer_date($niceAnswerTime);
#};