An update on this ticket:
SineSwiper added support for the REMARKS field from $dbh->table_info and $dbh-
Show quoted text>column_info in _table_comment and _column_comment in ::DBI.
Someone else (I forget who) added better support for MySQL, even though MySQL's
support for comments is very lacking.
There is also a generic mechanism available to store your comments in tables, a
table_comments and column_comments tables (overridable via table_comments_table
and column_comments_table attributes.)
What is left is to investigate and test comment support for other supported DBs.