I usually tend to create custom star systems for playthroughs and one obstacle I've come across is the limitation of orbital options for stars.
Being limited to the Primary, A and B stars prevents a lot of flexibility and requires a lot of planning before hand - though I don't mind it. One limit I've found is in the recreation of the Firefly Verse. Firefly's star cluster has a total of 6 stars and those systems have a minimum of 2 protostars in them, but I can only create 3 systems with orbiting protostars.
Another aspect of system creation was barycenters. At the moment I have to use stars as a place holder for twin star systems where they share the same orbit around a common barycenter, or with the case of planets, gas giants.
I don't know whether the program can grant more options with regards to this mechanic, as such I am inquiring on the possibility.