Jammers have their greatest effect when they can be positioned where an opponent cannot get to the unit with them, but the area of the Jammer forces them to overcome the effect before they can contact a necessary objective. Any situation where a Jammer can set up in total cover, especially total cover inside or on top of a building which will cost additional orders to access, in such a way that an opponent will have to contest the Jammer on their move up to an objective AND again in order to interact with the objective (and especially in those situations where they will then have to contest AGAIN a third time to move away) they become truly offensive. This includes Scenarios like Rescue, Capture and Protect and Looting and Sabotage but also Supplies and Power Pack. Playing building interiors, and the ways in which doors are played on those interiors, makes a big difference to the impact of Jammers, but isn't necessary for them to have a disproportionate impact on the game. Obviously some table setups are going to create choke points where a Jammer can have this impact even if it's not directly covering an objective, but this is more table dependent and can usually be played around. To me, it's the permanent aspect of the effect of the Jammer which is the key issue. Why is why I support allowing a "reset out" option for units which have been Isolated.