The key to this is ANPR, Automatic Number Plate Recognition cameras.
If your plate doesn't comply with regulations ANPR cameras might not be able to read it, there is no human element in how ANPR works. (unlike speed cameras).
This means cars with non compliant plates that should flag an alert don't flag up an alert at Police HQ or in Police cars. An alert might be caused by the vehicle being uninsured, having no MOT or tax, being stolen, or being of interest to Police for any other reason such as the vehicle being used in crime.
In my many years of Police uniformed patrol I used to give the friendly warning that Ali-G got if my ANPR camera couldn't read the plate and interpret it correctly.
If I saw the same plate on a vehicle again on a later date I would take a photo of it and send it to DVLA, they would often revoke the plate and send the owner a letter telling them their plate is revoked. (boo, hiss!)
The use of ANPR has resulted in thousands of arrests for all manner of serious crimes as well as the recovery of millions of pounds worth of stolen cars, so number plate regulations have to support it.
I 100% agree that number plates should be in the correct (unaltered) font/size and be readable by ANPR, but a small alteration of spacing shouldn't effect this.
I fail to see why the odd (very jobsworth police officer) will give a ticket for mis-spaced numbers if ANPR still reads the plate.
Here's a tale of a related event that occurred to me:
I bought a private plate and naughtily mis-spaced it to read "S R04CH M" which I am sure ANPR cameras picked up. (Worked in ANPR car parks, including the access barrier at my place of work which worked from a numberplate database.)
A number of years ago, I was driving across the New Forest (doing nothing wrong) and passed a police car travelling in the opposite direction. He was unable to turn around quickly because there was no space to turn.
By the time he had found a spot to turn around, he needed to drive his car at considerable speed, (past free to roam livestock) to catch me up. He pulled me over snd issued me with a fine and told me he would advise DVLA of the infringement.
I've since changed cars several times and have kept the plate legally spaced since as I don't want the police to have an excuse to pull me over for no reason.
Other than knowingly breaking the DVLA's number plate spacing rules (and my own vanity rules), I have always respected the law but my point is this:
Would a simple warning not have done the job?
Did the policeman need to put livestock lives at risk for such a minor infringement of the law?
This experience did leave me feeling that certain police officers don't do much to endear theirselves to the general public which causes harm to their public image.
No such problem with the wife's plate: