I have MultiPlus (shore) and MPPT (solar) chargers shown in Cerbo UI. The third charge source is alternator controlled with Nordkyn VRC-200. This charge source is show as negative Watt shown in DC load.
Yes you can fit a SmartShunt, but this has to go into the negative lead and most alternators use the engine for negative. On a boat the ability to have a negative shunt depends on how the cabling between the engine, hull ground especially on a metal hulled boat and battery negative is set up. If you have a single connection and no routes for secondary flows you can manage this.