Do you have a Cunningham or Boom Brake?
I re-purposed my soft vang as a cunningham with the addition of a hook. (I use it for maintaining tension on the luff if the halyard slips. I also transfer it to the reef cringle and tension the luff without having to put it on the reef horns at the gooseneck.) You can see the vang/cunningham fiddle block laying on the deck at the base of the mast. Then I bought the Dutchman boom brake. As you can see from the photo (Its not supposed to be sideways
), I swapped the clevis pins on the aftermost shrouds for a shackle. The line through the boom brake from one side to the other is a fixed length (eye splices on both ends). I added a block to the bale where the vang used to be attached, one near the gooseneck and one more at the base of the mast. The boom brake control line then goes up to the first block, forward , down and under the seahood to a sheet stopper on the starboard side. I can use the main halyard winch to raise the boom brake tight anywhere it travels on the fixed line depending on where the boom is on a downwind course. Better yet, the boom brake works just like my vang did. Even when close hauled and a rough chop bounces the boom around messing up the sail shape, tensioning the brake helps that. And I still have my topping lift. I can't reef easily without it. I elevate the boom (after loosening the brake and sheet) and pull the leech of the sail down to a reef point without a winch. Then drop the topping lift again.