I see. I thought that both are still using BGI, but it no longer the case. That said, from what I understand both BGI and Artemis are more or less the same, although apparently there's still some difference. I may as well test the partial patch later, but seeing that the thread was created in 2017, the translator may already have DMM version (ie New Edition) in mind.
Edit - Now that I have time to test the patch, I'd erratum my earlier post in that @Takeru1000 should get the New Edition here, because there's big enough difference between BGI and Artemis (Even though they basically the same), so yeah in case his friend still wonder which version to get if he want to patch the game, then I shall recommend him to get the old edition seeing that the patch is worked on using BGI in mind.