That's a very good description - exactly what I have seen. I've had to remind myself that the Victron BVM doesn't control anything - just sees the ins and outs of the shunt. It is programmed with the volume of the batteries (I think in terms of a physical volume for the watt-hours or amp-hours) and it blindly counts the in/out power thru the shunt. If it thinks the batteries are full, but current is still flowing into the bank, it just sits at 100% - current stops flowing when voltage reaches the charger cutoff, somewhere near 14.6 vdc, as I understand it. As you describe, the charging current may stop, or drop way down when you're not on shore power, and charging is only from your alternator or solar panels, so you won't be at 100%, even though the BVM says 100%. These LiFePO4 batteries are a big learning experience - I don't understand all I know about them. No wonder there's so many videos about how they work!