If you're farming all the oris available each week, I'm pretty sure you'll always be ahead in oris even after FLB'ing all the f2p event weapons we get to FLB.
So yea, you should be good to use the extras. Also the ori shop is supposed to get specific ori-only SSR wpns, but I don't know when they release in the shop. They obviously didn't release here with them already in it unfortunately.