That is what I thought at first, then I realized a couple of things.
1) The stock hubs are not auto locking hubs, they are full time hubs. This means your CV shafts are spinning all of the time and when you are not in 4wd they still spin, just they are disengaged from the diff. So if you install manual hubs and leave them locked all weekend (or winter if it snows) then shifting in and out of 4wd works the same. But you can unlock them during the week while you are doing your daily driving.
2) It's not really anything special about the Calmini lift which requires the manual locking hubs (I don't think) it's just the increased CV angles put more strain on the CV shafts which are already a weak link in the GV/Tracker so it would probably be a good idea whether you install the 2.5" Calmini or the 2" RRO lift.
I'm guessing the engineers thought this was fine because you are just spinning CV shafts and not a Solid Axle, but when you put more strain on the system with increased angles, bigger tires etc. then it starts to show some weakness.
I hope I have all of that information straight, it was actually one of my first questions when I joined this board.
Also take a look at this article: [link]www.zukiworld.com/month_030104/feature_tsb_shiftontheflyremoval.htm[/link]