I'm a huge fan of the Trails/Kiseki series from Falcom and I've heard this was similar. I also really like experiencing stories in chronological order, so I was just wondering if I could play the series
Prelude to the Fallen -> Monochrome Mobius -> Fallen -> Truth

I understand the MM spoils bits of the Mask duology but I was wondering if those were minor spoilers or major spoilers. Would they ruin my experience of the story or is the more akin to how Trails From Azure and Trails of Cold Steel II spoil each other? Or if a gundam analogy works, I watched Origin before the original trilogy despite the fact that it "spoils" MSG. Is Monochrome the same, where its ultimately the players choice, or does it operate under the assumption that you have already played the Mask Duology?