I recently had a look at a VX 40 /extreme40 cat mast. there the halyard is secured in the top of mast with a rather big clutch/cleat. This was only the top 30 cm/1ft of rope was under load [and therfore was some high tech line] the rest of the line was pretty std line, The release was done by a small rope which was attached to the release of the clutch/cleat and from there to the mast base

I could not see which brand it was [it was dark inside the mast....]