Quick answer, I would have thought it matters not unless the terminals identified as such. A long time ago I asked the DNO lads why they wlould not allow for a 4 pole isolator to feed an off peak and normal supplies and there answer was their supervisor had nitpicked because one of the terminals was marked "N" so you could not then have two Ns and two Ls and also for same reason the N must be the incommer N and the outgoer N was unmarked.
I was lay on my side reaching into a kitchen base corner cabinet to pull the fuse from one to see what it is and its condition.
So very restricted access to the main switch and the suppliers gear, I had a moment where I thought “”do I really want to do this?” and “”what can go wrong?”.
Or to be more technical I was lay in a kitchen cabinet risk assessing the inspection process.
That will be the case one way or the other. I am surprised if the terminals are not marked.
They are marked, I got one out of the back of my van and had a look at the instructions and the switch itself. This is one of those things I should know, as I have fitted a fair few over the years.
When connected correctly, bottom in, the fuse holder is isolated unlike when the meter tails are taken into the top.
