Ive done some testing on this. I desynth like a mad man pretty much every day. I have noticed with the early level stuff from 19-35 that you get a significant lower yield of FC1's. lets say your a GSM and you want FC1's. imo, you would do Electrum needles (Which is lvl49?). ppl have said mythril rings etc but after doing about 5000 desynths of both electrum needles were by far the best. I am lth, wvr and gsm desynth. When I am doing rotations for FC1's I use gsm and go that route because all my items are free (miner). I don't like lth when doing it cause I would have to farm hippo for an hour (no thanks) and wvr cause of threads etc. I guess it would be the same if you were to farm hippo/mine electrum but hippo is RNG vs mining. Both are mind numbing tbh. It basically comes down to what you can afford and how much time investment you want to throw in.