“… or even, is it an issue ?”
Depends…
If you have plenty of visitor parking and it is hardly ever full and, historically, you only ever have one or two units with surplus vehicles over their allocated spaces, and nobody is complaining, then its not worth bothering. Why not let a resident enjoy a convenience that is doing no harm?
On the other hand, if parking is tight and other residents are being inconvenienced because their visitors often can’t find a park, then it is certainly worth pursuing.
If there are residents with allocated spaces that they don’t use, perhaps you can play match-maker.