Frontier at that time, said the laptop was below the spec they recommend.
There's your answer, right here.
No amount of driver updates will make a graphics card more powerful, only more efficient.
When a graphic card is first released, a new driver can unlock previously untapped potential - but the GT 720M is quite long in the tooth now. And in the meantime, the game is likely to have become more, not less, demanding.
You could try overclocking your GT 720M, but I doubt it would do much good, especially in a laptop (with limited ventilation).
So.... shopping!
I'm not sure if I'm allowed to put external links in public Frontier forums, so will PM you with some options you could check out. If that £1k is still burning a hole in your pocket, it should easily be enough to get you fully setup for ED.