Thaumic Additions adds portals through the use of Arcane Seals. Placing one down and adding Praecantatio and Aer runic stuff to it, along with a third element to act as a key, will open a portal to any matching locations.
It also brings the ability to see through these portals, to get a preview of your destination.

Unfortunately, this see-through portal feature doesn't work long-distance, and is merely 2d, teleporting you to the destination when you get close enough.
Since the portal is circular rather than rectangular as you may be used to, and isn't entirely block-based (Minus the seal), I don't know how feasible it would be to make happen on your end.
I would, however, love to know, and would very much enjoy seeing this feature supported by you, though I understand if it cannot.