Major Description
PhoenixRuntime (the class that is run via the "psql" command) does its own custom command-line parameter parsing, which has a number of limitations. One of the biggest issues is that it depends on the ordering of named parameters vs unnamed (i.e. file parameters), and starts performing actions as part of the command-line parameter parsing. This can lead to some files being run/imported, and then the tool stopping with an error due to an unexpected command-line parameter.
An additional (but probably less important) issue is that the current parameter parsing is difficult to debug and test (there are currently no automated tests).