I’m not a big fan of the Safety Car anyway, I think it should be scrapped.
For the majority of incidents, they could just impose a speed limit on the cars, with no overtaking. This would allow the marshals to work in about the same level of safety as the first few laps after a SC deployment (where the cars have to stick to a low speed before catching the SC).
In more serious situations, the best course of action is a red flag. Line everyone up on the grid. The marshals can then work more quickly (as they have NO cars on the track to worry about), the race can get underway more quickly, and we don’t get a chunk of “wasted” laps behind the SC. Personally, I’d set a limit to the # of laps at limitted speed (or behind the SC, if they chose to keep it), maybe 5 or 6, after which the race is red flagged until the problem is sorted.
I know this introduces an unfairness to anyone who has built up a large gap to the car behind, but so does the SC (no matter what is done with lapped runners). I think the SC is an out-dated concept which is not needed in todays motorsport.