The minerals and moly are the additive package. These are the constituents of TBN.
Silicon can show that dirt is getting through your air filter.
Metals are the wear metals from the engine.
Sodium is a contaminant.
Yes the remaining TBN value ensures the oil hasn't become acidic. The EGR gases are acidic and will deplete the alkalinity of the oil over time. Low SAPS (Sulphated Ash, Phosphorous, Sulphur) oils are required for modern diesels to protect the emissions systems. Low SAPS oils sacrifice TBN and anti-wear additives. The additives can be supplemented, however your better off just using a quality Cj4 or Ci4 diesel oil that has an adequate additive package. There are some manufactures which still make synthetic Cj4 and Ci4 oils, so you have options.
The tested Cst viscosity can be compared to the Manufacturers starting viscosity to determine how the oil is holding up over time. Synthetics hold their viscosity much longer than conventional oils.
The only oil additives I've used in my VW Jetta TDI are Liqui Moly MoS2 and Motor Protect. Liqui Moly assured me these will not alter the advertised viscosity of an oil and will not cause any DPF failures. However these can increase the SAPS of an oil so there will be some impact on the longevity of your DPF.
https://products.liqui-moly.us/mos2-anti-friction-engine-treatment.html
https://products.liqui-moly.com/motor-protect-5.html
I plan to use the Motor Protect mixed with M1 Delvac Cj4 ESP in my 2.8 after break-in when I change the oil at 7,500 miles, and every 30K after that. in between the Motor Protect treatments I will use MoS2, one can per 6 qt oil change. Just like in my VW Jetta.... I've never used the lucas products so I can't comment on their efficacy.