I started a new game with a new modded faction and late into the game noticed that +500% was all I could get out of the hyperlane techs. Luckily, I had an old save and saw the percentage on the dimensional observatory was, in deed, +900%.
Then I created a new game with a base faction (Altarians) and the hyperlane tech still only showed a +500% bonus.
Okay, new game, same faction as the old save game (it was another modded faction) and still +500%.
What am I missing?