Well, that's pretty much the way it is, you can only research one thing at a time, and one lab is enough for that… of course, if you have something going on one one planet that temporarily keeps you from researching, then it'd be nice to have a few labs on other worlds, but don't overdo it.
BTW, Ascendancy - a great game; can't believe I only just remembered it after all this time when you mentioned it…