As long as all wheels are the same size it should be OK. Notify the insurer will depend on the insurer.
I had one ask me if the car had any factory fitted options. It was an 8 year old car and before the internet
had really taken off so little information on the net.
I just thought that insurer would be one that declined every claim and onyl paid out after an extended
battle. I chose to go elsewhere.
Best to mention it to the insurer just in case. It used to be the case when notifying them of my towbars,
they used to say no problem no need to inform them but more lately they seem to be taking notes
of things like that.