There are not safety issues with stretch tyres that differ from normal sized tyres, its all down to tyre pressures over anything else, they run the same pressures as you would normally put in, 32 psi or around that.
They can be driven hard on, i have done for years now and my stretch isnt what you would call shy.
Nothing to worry about, only thing, watch kerbs lol :) as for fitters, its all down to what size tyre on what wheel, i have done most sizes on most wheels owning cars so if you want to know if a certain tyre will stretch easy or not, just ask, more than happy to help as i know when its a major stretch, it is harder to fit the tyre compared to when its less.
