Another thing that can cause the weak socket contacts is the use of the stupid unregulated, zero standard so called child safety covers that fit into the sockets, because they do not conform to any standard they may be oversize and stretch the socket contacts. They also have other negative...
They will in my case, as my generation meter died after 10 years with the display going blank, apparently it is not an uncommon problem. Got it changed and sent in pics showing new meter with serial number to my FIT provider,
Brother in laws house had the system, 1st and only time I have seen it, disconnected and scrapped now, as above snake oil, his house still has damp not as bad now he has sorted out a lot of the causes.
Think you would struggle to just go and sit the exam without any course hours.
Haven’t done the 18th as I am retired now but did the 15th 16th and 17th and put in the course hours before sitting the exam.
Just to add to the top information above, I have seen and dealt with Bayonet Cap lamp holders where the max wattage has been exceeded and the parts that failed were the wee springs that press the brass contact onto the lamp (bulb), the springs were no longer springy.
I can only echo what has been said already, I only really fitted MK but that all changed about 20 years ago, MK went from being top of the class to at best average. Click Mode for me now.
Re Crabtreee I have fitted a few of them and they are good I just keep forgetting about them except when it...
Going back about about 15 or 20 years or so and I was organising a first aid courses for a group of us and it was the basic 3 years refresher with an extra 1/2 day (might be wrong with that bit) to cover additional electric shock first aid this bit covered AED and oxygen administration.
Keep accessible would be my answer, you can get small earth pits, basically a box with a lid that sits on top of the rod, in you are laying a new concrete apron I would fit one of them with the lid flush with the top of your concrete, allows access and will be unobtrusive
None that I can think of, might be prudent to mount any electrical kit on a Heat resistant board. In fact does @johnb2713 on here not have all his inverter, batteries and bms mounted in a small wooden lean-to against his house.
Edit Binky beat me to it😀