Merc will be paying for the privelage for a start. Second it’ll be performance, the car has to be fast enough and driveable enouugh on all grand prix tracks to lead the F1 cars at a decided requsite pace.
Around the accidents it’s simply a matter of tackoing the right route but keeping the F1 cars at a certain level so the restart is safe is the most important thing when considering how the saftey car should perform.
They also need to fin a way to get the cars in order, I know people say that allowing lapped traffic time to unlap themselves takes to long but it’s better than loosing race situations, or loosing even more time to the procedure as the front runners unlap themselves under race conditions.
I know racing after the re-start might feel a little artificial but it’s exciting enough to make up for the time spent lapping in order.