In a charity shop I found a book with 'grandfathers best advice on gardening'.
It says that a cylindrical support is actually a traditional way of supporting peas and beans. They are using the space more efficiently than straight supports.
A mesh cylinder with a diameter of 1 metre supports 3 metres of peas. If you want to be able to enter the circle, you need to make an entrance of about 50 centimetres. That still leaves 2,5 metres of peas supported on a one metre stretch.
The advice is to keep 20 centimetres between the cylinders.
So northerner, you're not giddy at all.