Sadly, as an enforceable standard HDMI falls very short, since everyone is allowed to do pretty much as they please (as long as there is an HDMI terminal in the line) there will continue to be a lot of failures.

Of course there are some things that you can do to minimize the frustration.
#1: Get to know your Factory Reps & Techs (if they know you they may be more forthcoming with honest answers).

#2: Try when possible to use repeatable solutions (not a perfect answer, but a somewhat reliable one).

#3: When in doubt, call me (I can be much more detailed on the phone than I can in print).

#4: Plan for the Future NOW!

#5: This is a hard one. Expect failure (sorry) and the need for adding some repair devices to make system work. In other words do not make quote without some buffer to allow the install of fixit devices.

#6: Keep the phone numbers handy for the following people. They know their stuff.
Jeff Haynes & Zon (Zektor)
Matt Murray (AV Pro Connect)