Optimization with no U-Turns at Via-Stops

Routing engines support u-turn restrictions at via points. This is important for large delivery trucks as they are not able to change driving direction at each pickup or delivery stop. Especially when if stops are very close to each other in the neighbour street or even on the same street segments u-turns are a not wanted a all.

My problem is I did not find yet a solution for disabling u-turns at stop order optimization. The result of VRP would be completely different if no direction would be allowed at the via stops.
Is there a way to solve this with the help of some soft or hard constraints of jsprit?

Another problem is for large streets it will not be wanted to have stops on the oposite side of the road. The stops should only be alowed to be reached from the driving direction side. In countries where you drive on the right side all stops have to be on the right side of the bigger road. OSRM has a parameter setting called approaches=curb => is there something simular for the jsprit engine.
Because I would need both approaches=curb and u-turn-at-stop=disabled and this is not supported by OSRM as far as I know; what about jsprit?

Would be nice if you could help on this topic.

I think it would be a good idea to add a customized cost and distance time matrix to the Jsprit, in that case you can inforce specific distance for the route(in your case will be longer uturns) and variable speed

JSprit is not a routing engine, but the GraphHopper routing engine does support curbside constraints (similar to OSRM). The route optimization endpoint of the GraphHopper Direction API supports this as well: Documentation - GraphHopper Directions API