The relevant action in the invention is:
command = { type = addcore which = -1 }
The -1 command gives you cores on random, non-national provinces, which
border your country. If -2 was substituted in, then it would give cores on random, non-national provinces,
inside your own country. In addition, -3 would give cores on random, non-national provinces, bordering your national provinces (
in the country or outside).
Basically... the -1 'which' value is the only definitive way to gain cores outside your national borders. The other two do (or have a chance to) give cores within your national borders, thus not stimulating the growth of fascism. Perhaps a future patch could tackle this, however, and allow for a fourth option of cores on provinces that border your national provinces, when your national provinces are on the border??
The countries that experience fascism are the ones that are likely to have lost a war. Therefore, these actions in this invention seem pointless to me. Fascism should only get big if it was due to ACTUAL revanchism in-game, not if the AI considers more land as it's national provinces just down to having an invention.