“As amended” means as the Nationality Act changes, the latest Nationality Act applies to GV holders too. Have you run your optimistic and innovative statute interpretation by your lawyer?
Suppose the parliament passes the law tomorrow to amend 5 years to 10 years, and the constitutional court does not rule it unconstitutional. Suppose you have not submitted your naturalisation application by the time the amendment become effective. Do you get to apply after clocking 5 or 10 years?
Anyhow, it was not my intention to derogate. Hope for the best indeed.