Cool, thanks for the quick response.
The two-sided material suggestion helped loads. It almost completely removed those large gaps we were seeing.
I’d previously tried the ‘recalculate target on every frame’ option before, but it had destroyed the framerate on lower end devices. I hadn’t considered reducing the tessellation count while this was active though (and these days we have a version of this ribbon effect for low end devices anyway), so was able to use your advice to find a very happy medium between the settings 
Thanks again