Agree, but (there's always a but!).
I think, however, where it comes from is the incidental work that may be required.
For example, if you follow the AML installation instructions to the letter, without 'drawing outside the lines.' Then, no problem.
However, where mod work is required, then an EO will probably be required.
A good example of this is adding a long and 'heavy' box to a '60's style rack (think EX600 in a baron panel, old cessna, PA31 etc) if the rack rails are the result of 40 years of Swiss cheesing, you will either need to replace them, or insert a brace.
I don't know about you but if I were the signatory responsible (given our 'user-friendly' mod laws) I would need to see an EO.
In a PA31, the back of those racks are less than 15mm from the chain that connects the two control columns. Were the rack to 'sag' it would very likely jam - bad ju-ju.
I'm not arguing that it's right, but I have seen many examples of where an EO has effectively been required.
Again, for the avoidance of any doubt, I'm not advocating the necessity of our friends' CASA's laws; merely the compliance thereby.