The TIS article which I linked is from early 2019, and you can see that several engine models have non-LL01 recommendations listed. For the B58 and B48 without PPF, for instance, LL17-FE+ is the preferred oil. N55 remains LL-01 outside of EU.
I would think that if the US ULSG and Canadian Jan 2020 sulphur specs were low enough for them they would change some of the LL-01s to LL-04 for Can/USA.
I guess that even though spec approval isn't vital to me, I'm not necessarily confident enough to go low SAPS against recommendation without knowing exactly what I'm getting into. Am I fine as long as a TBN/TAN test in UOA says I did not exhaust the oil? Is that my only risk of going low SAPS? If that's true, then I'm extremely unlikely to see an issue with my relative short (for the quality of oil used) OCIs.
Euro sulphur levels are at 10 mg/kg. Here they are 12 mg/kg, not a whole lot of difference. Five years ago they were 4-5 times that high, or even more. In fact we have been on lower sulfur fuels for longer than the USA has, we are ahead of them in this regard. If you read the link earlier it says 12 mg/kg is the goal but some refiners will go on a pool average which can allow up to 80 in one batch but the average must be under 10.
So if they choose that option you may have a batch at 80 but then you'll have twenty batches at 7, for example.
The sulphur turns the oil acidic faster, so you need higher TBN to combat that. The full saps oils have TBN around 10-11 usually, the low saps it is more like 7.5-8. So, in a high sulfur fuel environment the oil will become acidic faster.
Keep in mind however, the low saps oils are approved for double
the oil change interval in Europe. Now, this is true with VAG, I am not 100% sure BMW is the same, but I imagine they are. The full saps stuff is 15k (km) or one year, the low saps is based on the vehicle OLM which can be up to 30k or two years. So in low sulfur environment the long term viability of low saps oil is absolutely no concern.
I suspect BMW may be concerned with ethanol content in fuel here which is why they still use full saps. I believe in western Europe it is not really normal to have 10% ethanol.
I have a 2018 RS3 and as I said before it is the first engine in North America VAG approved for use with low saps oil, it is the only
recommended spec for the car. The normal service interval is 15k, I only drive about 12k per year so I typically do that. Starting in 2019 low saps oils (504, 508) went across the entire range.
Another thing to consider is the low saps oils stay in the TBN range of about 2-3 for a long, long time. They do not drop linearly. So if you have a starting TBN of 8, do a TBN check at 10k km and it's at 3, it doesn't really tell you much other than OCI of 10k is very safe. The oil could take another 10k to fall from 3-2. I can't explain why it does this, I am not a chemist, but this phenomenon has been consistent with low saps oils for many years now.
IMO you have absolutely nothing to be concerned about with LL04 especially with your service interval of 6-9k. If the car burns any oil I would also be more inclined to use it because of the added benefits and you're also adding TBN back in with new oil.