Add a Policy Fee column. By having this data readily available
in the Calculation Summary, a user will save time from having
to copy the full illustration data (Ctrl-D) in order to get the
information.

In addition, a number of users would prefer the Calculation
Summary and Supplemental Report columns in an alphabetical
arrangement.

This item
  https://savannah.nongnu.org/support/index.php?105978
(marked as a duplicate, and therefore closed) suggests
adding columns for honeymoon rate.

More recently, we've received a request to add a column
for pay-as-you-go "minimum" premium, which some agents
find useful even with a single payor who pays more than
that minimum.

The palette of columns offered for supplemental reports is not
yet ideal. Some columns aren't valid. All could be named better.
Other columns would no doubt be useful. Users ought to be able
to store column selections and reload them by name. More than
one supplemental report per illustration should be allowed.

New columns might be functions of existing columns, e.g., simple
arithmetic (C0 + C1 - C2), or the IRR of column C0 versus C1. It
is important to consider whether such columns should be calculated:

 - always, in C++; but that would require more RAM for every
   cell,and IRRs in particular are expensive to calculate;

 - on demand, in C++, which is probably best, but requires
   careful design; or

 - on demand, in xsl stylesheets; but that would probably be
   slower than C++ and less accurate (because operand columns
   are rounded before xsl sees them), and it's certainly wrong
   to calculate IRRs in stylesheets.

A GUI to design such additional columns would be ideal, but
far more ambitious than a menu of predefined columns.