Include doctrine/dbal in vendor libraries
Since WHMCS provides the really handy Illuminate\Database stuff for doing queries etc., when developing my addon module I implemented the module_upgrade() function, where I can create/drop tables, or modify records in them. However, it is not possible to alter tables.
The problem could be easily solved by adding require doctrine/dbal to the composer.json file, however WHMCS does not provide this file with the release.
So maybe you can add doctrine/dbal in the next release vendor libs, question mark? :)