Ok, change of heart, I'm keeping the pellets running.
After speaking with Ian, seems he & I are in the same mindset that it might just be a nutrient shock that you sometimes see with LPS after starting an aggressive ULNS system like Zeo. Since the feeding responses are still strong, I'll just have to step up the feeding of these guys. Plus Ian had a pretty good suggestion of using Sponge Power (SPONGE POWER!!!!!!) and LPS Amino Acids, I figure it probably can't hurt to try it plus I happened to have both anyhow so won't be costing me anything to try it.