Diesels place particular demands on oil. While thin oil has many advantages, an automotive oil, engineered for fuel economy, won't contain the additives necessary to deal with excessive carbon loading, high acid content, higher internal engine loads and possibly camshaft lobe loads.
It's always best to use a diesel rated oil in diesel engines.
Don't think that because your exhaust is clean that the engine is also. It's as dirty and as tough on oil as any diesel. There is no magic there. For example: modern diesels have high rates of EGR flow, introducing massive quantities of contaminates into the oil, through blowby past the piston rings.
Choose appropriately.
If it were me using a NON STANDARD OIL, I'd pick an oil with a robust additive package and plenty of acid combating capability. Then perform early oil changes and Used Oil Analysis.
You might be best served by a PAO based synthetic, as they remain considerably thinner when cold compared to conventional Group III synthetics (which are simply severely hydrotreated dino oils)