One thing you could use for more test cases is the book 101 BASIC Computers Games by David Ahl. Games always encouraged people to use computers and that's as classic as it gets!
The linked page has this to say:
"Disk I/O ā SAVE, LOAD, MERGE, FILES, KILL, running directly on the UEFI Simple File System."
BASIC requires more support than you'd expect. Here's an interpreter, with a similarly long list of features it has to support:
I am investigating whether it would be feasible to do something similar for Python.
Considering how much it supports, if it could chainload a full operating system, it would make a great replacement for GRUB or rEFIt.