While not really a legacy or old relic weapon yet...

Maybe have the Fates and CE's in Bozjan southern front drop those memories for that really early step of the bozjan relic quest line where you need 15 of 3 different types drop 100% of the time in the Bozjan southern front? That really seems like the most time consuming step of the entire thing for making additional weapons as you either sit in bozjan southern front hoping RNG gives them to you, or you run around on 3 different full size and much larger maps doing 15 fates each on them.