I'm reasonably relaxed about this Tom. My Roadster has the main bank of fuses on the bulkhead. Recently I pulled them (eight) and just polished the contacts, which were slightly tarnished.
The bank of twenty fuses under the dash is hard to get at so I only go there when I have to, such as when the horns stopped working.
The single main fuse in the rear cavity I would only check if I was in there.
I found the problem under the dash of Bumble (2012 4/4 75th Anniversary) when I was tracing a hiccup in the engine over bumps. The fuse was half out of the holder and I added cable tie to hold it in. That wasn't the cause of the problem though, which was a loose connection on the engine.