I really don't know how many different versions of this HFT is being practiced in the UK as I have seen videos of some HFT comps on U tube with the shooters apparently allowed to fiddle with their scopes ala FT and with more freedom in their stance and kneeling postures,. Confused you will not be after this episode of the HFT SOAP.
When I and my shooting friends have an informal practice we tend to abide by the normal HFT rules regarding stance and scope..
A.G