NY formulated on Friday :
But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage in
having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other? Is a
single socket block with 12 sockets in any way safer than a 6-way with two
4-ways plugged into it?

No safety issues, unless the adaptors are maybe cheap Chinese items.
Mainly it will look untidy, but better/safer than a long trailing lead
across a walking space.