It depends massively on the local property and connection circumstances…and let’s face it who you get on the day and your mutual agreement! 😉

The basis is that the point at which the external grade cable transitions to an internal grade cable must be as close as possible at the point at which external grade cable enters the interior space of a property - that is big no, no is running black cable inside a premises for OH&S reasons. Also the CSP must be located where it’s safe and practical for the engineer to splice the fibre, now and in future if ever the internal connection needed to be moved or re-spliced.

As such there’s some degree of practical latitude in agreeing a siting position for all these things, bounded of course by what is realistic / practical in said setup/situation.

I didn't quite get that right, there is a location at the Master Socket that (in my opinion) would be ideal, easy access, not in the way, easy access to power - providing they are reasonable sized boxes, which I now know they are.

That being said, I have a row of kitchen cabinets along the wall under the stairs and one of them has no back, the one at the Master Socket. Their is a double power socket on the wall. It isn't a tight confined area, yes it is a bit enclosed but I think it'll be fine.

IF it can't go there I am really not sure where else it can go.