I'm in similar situation but with a binary system with a very huge gas giant (and several interesting moons) at +90b and 3 LP: you may think "Ok, jump on the relative LP", unfortunately the distance between this planet and the relative LP is greater than that from itself and the other planets, something like +95b... The only thing that I can do is a TF with a GeoSurvey and a megatanker/supplier and... a lot of time. Please, we need Hyper technology!
Ya, I think that's purposeful, or at least the way it is (if not the intent of the Almighty Steve). The LP is always 60 degrees trailing behind the body of which it is the LP, meaning that the LP, the super jovian, and the sun it's circling from an equilateral triangle. So jumping to an LP and going to the super jovian is always going to be just as long (longer, counting getting to the other LP in the first place) than just going straight from the sun to the body.