R280, the basic plot seems reasonable,however,if the `package` is injured,rather just compassionate,then the ship should continue to SG,to give the injured best chance for earlier /better medical treatment on board.
Then,I would suggest that a `moving Crit Point`is considered if the Lynx should have to do a return to Mother in the event of a single engine failure and return at a lower speed,ie 90 kts,or continue to Grtvkn,in which case the ship will go there as well...!
Lots of things to consider...