Rubbish.
it's no different to ILS having CAT I, II and III with different design and equipment requirements. If you only fly to Cat I then it's pretty simple. If you fly to Cat II or III then its more complicated.
The information is out there if you care to take more than 3 minutes to understand it. Dick, there was nothing in my post about whether you have to fly the approach with AP coupled or not. You can couple to them all, it doesn't care. If you are flying to LNAV minima then monitor the intermediate step heights down to the MDA.
If you are flying to LNAV/VNAV minima then make sure you have an accurate QNH and are in the temp range, then just worry about the DA/H. Not that hard.