In breeze up to 10 knots you should be fine if the outside blocks have the ratcheting enabled and the beam mounted blocks are disabled. Over 10 kts and you want both on, for most crews. When distance racing we run doublers to get 2:1 purchase for long spin runs-put a block on the sail and a hook on the shroud attachment point, run the sheet through the block and to the hook. Makes jibing a pain, again it is a setup for distance racing only.

Cleating a spin sheet is asking to go swimming.