I have an idea that I think a lot of people would like.
What if the portal system would check for the keys the toon is holding before opening the interaction window, and you would have the following options
1: Center on Minstone
2: Prantz on Dregar
3: Arnax on Belinara
4: Key's destination
5: I do not want to jump
When the character would select key's destination, it would show the door numbers for every key the character is holding on him/her. Selecting one of the number would 1 either transport the character at the portal location of that house, or outside the house, which ever the GM's would prefer.