Looks interesting. One minor point: I most commonly use Class ();. Before I read the full docs, I guessed that ... Class => '' ... would give me that, by symmetry with the other available options:

  Toolset->export(
    Class => 'sub1 sub2',
    Class => ''
    Class => [qw/sub1 sub2/],
    Class => [],
  );
[download]

I'd suggest making it so, and leaving undef as the only way to get use Class;.

I think I'd rarely use this for applications, where cut and paste can happily replace repeated typing, and where there are benefits to having the modules and pragmas in use clear to see.

But for command-line invocations I can definitely imagine using this - when testing my work application, I often need 100-200 characters on the CLI just to get all the modules and initialisation I need, before I get to the one method call I'm trying to test.

Hugo