I haven't looked into it, but I doubt it will be much harder. You can probably expect the need of a higher spike damage for the last boss or something.
But, remember that even relatively new people NEED to be able clear this thing or their progress gets CUT OFF ENTIRELY. The idea of putting Ori into GO only, then gating progress behind Ori, and then making GO much harder... is only a good idea if you want to KILL YOUR GAME. I'm not saying that DMM is absolutely smart enough to not go into a trap like that, but hey, we'll see eh?
So, if you are going to farm water rag do you need the soul weapon for Andro?
Need? No. But it sure helps. Particularly the Burst effect which boosts your healing output by a fair bit, but that's 120 Regalia.
If you don't have an excess of 120... well, skip it I guess. Or you can run 1. Basically all you need for Water Rag is two people with Andromeda and one hour of AABing.
... are you going to? The droprate on those things is awful, the exchange rate on those things are awful, and their other use (Magmas) also have an awful droprate. Doesn't seem like a good deal to me. Particularly since if you can't clear GOs, you're not going to do much against Rags. Just giving debuffs is good enough, I guess.
Apparently next tower is Wind, lucky for me since my strongest weapon grid ATM happens to be Fire. I'm a rank or two away from having enough soul P to unlock Solomon, and I'll have enough regalia after monthly shop reset for her weapon. Do I only stay at LB0 for Solomon's soul weapon? The burst effect doesn't seem all that great. Instead it feels like Solomon only needs 6 MP in ability damage and her Hour of the Overlord MEX, her soul weapon seems to be only important for giving her an aoe.