(REQ) Make black market more visible on map

[XTC0R]

Can we give the black market dealers give the same visiblity on the map like shipyards, wharfs, EQs, trading stations?
I like to visit them from time to time but they are hard to spot on the map. Only workaround is using the ware filter set on illegal wares. But this also gives a lot of false positive.

Alternative: Make it possible to open the legend and select one item. Only this item is visible on the map.