It would be interesting though if there was just a bit of lore or a small quest or two woven into the present day as well. Maybe some NPC uncovers a leftover stash of grenades, which you have to destroy. You can use some of them but only during the quest. Or some remnants of battle plans left behind are uncovered. Or Sarah has new dialogue about the "strangely armored" people that saved her long ago. Just a little extra taste somewhere

ETA: Yes, I am aware that Sarah exists in the Underworld. That was kind of my point, possibility that she might say something extra about being saved
