Maiden Japan, that looks great and like it will be HUGE!
Miriya, running a scribing tool (several times) is really about it unless you saw or machine excess away. Scribe at least half the thickness and bend it to break it off. You can score more shallow, but the accuracy of your cut decreases. Yes, then you have to clean up the edges, but that's life!
On the positive side, a Fiskars rolling cutter IS the BOMB for thinner plastic like .020" - -perfect for strip cutting too. NO raised edges, just cut and glue! - MT