I'd prefer something a bit more artificial looking, like our targeting scanners or whatnot were focused on the wormhole:
The trouble with this is that it doesn't seem to rotate properly.
Also, if a minimap showing everything would be a performance issue, what about a selective minimap? All non-turret static structures could show on the minimap: stations, power stations, special assets, etc. They could blink when attacked, and the wormholes would also blink or have a ((o)) glyph indicating incoming attack. No need to render every last ship on such a tiny window.
I've lost my share of (glass) Ion Cannons because I was focused on another area of the battlefield, this would help me out a bit.