On our previous two boats the shroud on the RF drum was not adjustable, as I recall one unit was a Hood I don't recall what the other was. The Hood had a big nut on the bottom but it did not allow the shroud to be moved/turned.
How do I know that you might ask? I had two club members, both power boaters, assist in stepping the mast one spring. In the midst of the confusion I put the pin in the forestay 180* off so the opening on the shroud was pointing forward, not aft. GOBI?