I don't know for sure whether it will effect your insurance but as I see it the trouble with mixing tyres is that it's trial and error whether they work OK together.
Manufacturers don't test different brands of tyres for obvious reasons, and they sometimes don't even recommend mixing some of there own tyres because of individual characteristics of certain tyres.
It all just seems a bit too risky for me.
We rely so much on tyres when riding bikes.
I like to know I'm riding on a matching pair of tyres, suitable for my bike, which have been fully tried and tested but each to there own.
