I got my private plate in August 07 & wasn't happy with the plates my local autoshop made up for me as it had their advertising on the bottom, I wanted them plain. So I did some online & yeah I moved the space. Instead of XX_XXX it goes X_XXXX. This now becomes my first initial & surname, it looked good before but looks even better now.
I've never been pulled for them. I keep the correctly spaced plates in the boot with a small screwdriver just in case but whenever the police are behind me they just end up turning away somewhere else.
I've also suspect that their number plate recognition system doesn't recognise the spaces, as some people have those double decker plates, as do many bikes.
I still need to put on the correctly spaced ones for MOT, forgot last year but the mechanic I use put them on for me, he is as sound as they come.