For scrubber vessel force consumption of LS fuel on board first before switching to HSF

In some cases a scrubber fitted vessel may have LSF fuel on board that they want to consume before switching to HSF. There is currently no way to override the scrubber consumption to force the system to use the LSF first.

Scenarios
a) Vessel previously bunkered LSF because no HSF was available. Now need to burn this fuel to free up tank space for more HSF.

b) Vessel has LSF on board that is cheaper than currently available HSF.