This has previously been mentioned by most brits about our HART service but there is one problem if something similar to it would be added and that is access to it. There bases cover vast counties which means they cover a large area. The problem faced is that if built the person who built it would be the only person who can access the units. This makes it hard if other players the area in which the HART units cover being able to use them as they would have to contact the player who owns them which is hard sometimes to do. So my idea is being able to share a station which they are housed in, the player who has the base in the area would be able to select the people what can use it and they would contribute to the building of the base. This makes it fair to the player building the base but also useful to the player that would use it as they can access the units as when they are needed without having to wait for help.
It may sound complicated but it could work, whether it's added no idea but it's just another suggestion.