The typical bypass system will be "absolute" around 2-3 um, brand dependent. Most UOAs that are ICP based or something similar will see everything below 5um or so. What becomes common is that the very small particulate will continue to escalate in count because the BP filter can't catch the really small stuff. But stuff that small rarely does much harm to the engine; it just free floats for the most part. OTOH, some of the larger particulate material is removed from view in the UOA with a BP that would normally be seen in a UOA without BP. But if it's not in view, it's also not in the oil stream to wreak havoc, either.
What we need to realize is that comparing UOAs, one using BP and one without, isn't really "apples to apples". I have over 16,000 UOAs in my database, many of those have BP systems. So I have a good base for comparison. The thing to understand is that systems which run long OFCIs with BP in place, have different profiles for long-term use. Though the BP element does a great job of removing a lot of particulate which is very harmful to the engine (5um to 15um), it won't get the really small stuff (below 3um) with any real efficiency, and so the small particulate just continues to accumulate in long OFCIs. But the ICP UOA will sense it, so it seems larger than what we'd see in a traditional OFCI because those flush out the really small stuff with regularity.
This lube is suitable for continued use IMO.
I would agree with mattd; caution is the proper word, not panic. Continued monitoring is warranted; the Al more so than the Fe at this point. Run it another 5k and sample.
