If your trying to research all of the upgrades and can't because of the 8 upgrade limit (I think it's 8) on star bases, here is the line you need to edit to allow more or all the upgrades to be researched:
(StarBaseTech.entity file)
statCountType "StarBase"
maxUpgradeLevelCount 16
UpgradeTypeCount 8
As you can see I have my maxupgradelevelcount doubled to 16, hope this was what you were asking and it helps!.