Let see where do we start:

1/ The roof and panels, are we bonding/grounding the solar frames or installing ligthning protection, it seems this has become a combined all in one solution ? If you installing a 16 mm wire for lightning protection surely all the bonding between the rails, panles and any other metal, should all be done in 16 mm and it sahould be one continuous run, not using the panels and rails as part of the continuity path. If you look at real lightning protection and read the documentation revelant to lightning protection, things like the class 1 and class 2 protection must be identified and it must be carried out accordingly. Can you install class 2 protection in a building which has calls 1 protection for example? I need go scrap in my filing cabinet and find all the domentation form when I did courses and attended semininars on the topic.

2/ The home made DC control/combiner/fuse panel/DB, maybe we should identify a common name for this box.

3/ "Homemade" DC control box, some might say it is not a DB, otehrs might say it forms part of the solar system, so its a control box not a DB and therefore the things like the mount height etc dont apply.

4/ The fact that these DC control boxes dont actually isolate anything due to the fact that double pole isolators/circuit breakers are being used, the fact that you switch off the isolator and still have power on the top and bottom of the isolator gives it a false sense of isolation.

5/ Live wires in the DC control box which cant be isolated unless you use a ladder to climb on the roof and unclip cables and are not clearly identified, so first have to find which MC4 is supplying the DC control box, there is no islaotr on the roof to switch off, the more I work on these the more nervous I get. Now I can see why comercially made Dc combiner boxes have MC 4's attached the the box. If you you remove MC4 there are no live wires hanging loose inside or outside the box. NO need to climb on the roof to try figure out which MC to unplug. Which could reuire safety harnesses and all thos things.

6/ The neutral earth bond, well that will go on until the DOL step in and issue a notice.

7/ Safe isolation notice, clearly identifying what must be done for elctricians who are not aware of how solar systems work, or in case of emergency

8/ the in case of accident leakage label, some people still have this notice attached to DB's with dual supplies. This notice requires attention and should be modified to suit the application.

9/ The changeover/bypass switch, the cabling in and out (the proction for the cabling), the circuit breakers and isolators used including the wiring configuration, requires too many veriable and too little focus on the application.