Beyond the Dawn DLC + Peak Strength (Level 100) Trophy...?

[longislandviper]

Hey! Quick Q I was hoping someone might help with.

 

I'm near the end of the game, and am cleaning up side quests (etc.) before going to the final story dungeon. I'm in the mid-40s level-wise. I see that there's a Trophy for achieving level 100 (Peak Strength), and it explicitly notes that this must be accomplished in the "main game story." So (considering that) this may be a stupid question, but does anyone know if you indeed have to grind to that level in the core game itself? Or could I play the post-game DLC at a sub-100 level and use that experience (literally and figuratively) to aid in getting that Trophy?

 

Maybe these two things don't even intersect when you start the DLC -- I have no idea -- but I'm trying to plan ahead, and I'm wondering if I should even bother with the Plat or just beat the game, do a little clean up, and move on short of 100%. Grinding 50-ish levels just 'cause (even with the optional bosses and dungeons) seems... eh. The DLC would help a lot, but I must admit the longer the game goes, the weaker it gets for me.

Thanks for any help that can be provided. -Colin

[longislandviper]

I wanted to come back to this with some clarity, as I've Platinum'd the game. I could have just done deeper research and figured this all out earlier, but in case anyone has the same question as me:

The DLC runs off of a fundamentally different save file, and you can actually play it without having even beaten the original game. However, though I was level 100 in the regular game, I was brought back to level 65 upon starting the DLC, which is what happens for everyone. So, there's no way to combine the two, which is a bummer... but grinding in the campaign is actually somewhat negligible, all things considered, by fighting the optional dungeon bosses.