Irrelevant for speedway. However they can be uncomfortable - with speedway it's really important you can move your body about easily, this was one of the attractions with modern suits over leather because protection wise I don't think they're as good. Adults make choices with risk, that's life.
All sounds positive. I admit though I'd never heard of "reinforced grass" before - that will be time consuming, inserting the steel wire into each blade (I assume that's what it is 🙂)
I've ridden the track with a 'blue grove' back in the late 90s so it's not new. However, riders do ride differently now and the tyres are also different. Peterborough and other tracks had trouble with that I remember. But, whatever, the track was not responsible for Ipswich losing.
So what? Leicester still got around there the fastest, both inside and out. The days of deep tracks are over, riders no longer like it and the tuners/designers have ensured the bikes can no longer cope with it.