How to prevent large rice noodle from curling?
I ate those kind of noodles as you showed once many, many years ago and IIRC those noodles taste like dried Pho noodles and have the same texture. To stir-fry your noodles I suggest to soak them in cold or at maximum luke warm water first1 and then stir-fry the softened noodles. Due to pre-soaking, hopefully there should be no uneven hydration and thus, no curling.2 I've seen many people preparing Pho, Hu Tieu or sti-fried Pho that way without any curly noodles. 
Depending on how thick your noodles are you might have to blanch the noodles before stir-frying. 


1 For 30 minutes? I never paid attention to the time. They don't get mushy if soaked longer.

2 YMMV: Another advantage: You might be able to prepare the noodles beforehand, so no blanching directly before stir-frying or having sticky noodles if not fried immediately.